All plant cells are capable of taking up water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger. In common land plants, the living cells of roots take up most of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.
Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度). In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies. In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.
64.From the passage we know that the evolutionary scale is graded according to _______ .
A. evolutionary
cycles B. heights and depths
C. time D. kinds
65.The “bromeliad” is a plant that _______ .
A.has useless roots B. is a pineapple
C.can grow anywhere D. takes up water through its leaves
66.The most suitable title for this passage is “_______ ”.
A. Absorption of water by plants B. Rootless plants
C. Plants in the desert D. Higher plants
Microwaves may be great at warming up food, but what about warming people?
Using microwaves to directly heat owners of
a room would save much of the energy wasted by heating walls and furniture. And despite popular ideas about microwaves, this techniqu
e would be safe, according to Charles R. Burlier of the Microwave Research Center in Marlborough, New Hampshire. Low-power microwaves only penetrate (贯穿) the skin (low-power microwave penetration in a ham is about 0.2 inches, for example) and with no negative effects.
To test this idea, Buffler subjected himself to microwaves in a special room using a standard 500-watt, 2459 MHz magnetron (磁控管). He found that a person will start to feel warmth at about 20 kilowatts per square centimeter (mw. / sq. cm. ) ; a satisfactory feeling of warmth occurs between 35 and 50 mw. / sq. cm. By comparison, a person standing in noonday summer sun feels the amount of 85 mw. / sq. cm. And a frozen meat pie in your microwave oven receives about 1000 mw. / sq. cm.
In houses of the future, each room could be provided with its own magnetron, says Buffler. When you stepped into the living room, for example, a motion detector (运动感应器)would turn on the magnetron, filling the room with low-power microwaves. In the same way that a microwave oven heats up a hamburger, but not the plate it’s on, you would feel warmth from the microwaves without changing the temperature of your coffee table. (You could, however, make your favorite easy chair even more comfortable by treating it with a radiation-absorbing chemical.)
While it might be some time before homeowners are comfortable enough with the idea to set up whole-body microwave heaters in houses, Buffler says microwaves may attract livestock(家畜) farmers. Lambs that are born outdoors in winter, for example, are frequently lost to cold. Microwaves could warm the lambs safely and quickly. Which of the following can tell the main idea of the passage?
| A.A new heating system. |
| B.A new microwave oven. |
| C.A popular technique. |
| D.The magnetron. |
According to Paragraph 2, which of the following does not describe the characteristics of a microwave heater?
| A.It directly heats people in a room. |
| B.It heats walls and furniture in a room. |
| C.It is safe. |
| D.It saves energy. |
The test conducted by Buffler shows that when a person feels comfortable warmth, he receives about ________________.
| A.20 mw. / sq. cm. | B.40 mw. / sq. cm. |
| C.60 mw. / sq. cm. | D.85 mw. / sq. cm. |
According to Paragraph 4, which of the following fills the room with low-power microwaves?
| A.The magnetron. |
| B.The motion detector. |
| C.The microwave oven. |
| D.The radiation-absorbing chemical. |
Which of the following statements about
microwave heaters would Buffler most probably agree with?
| A.Microwave heaters will soon be widely used by homeowners. |
| B.Microwave heaters sometimes make people feel uncomfortable. |
| C.Perhaps microwave heaters will be first used by livestock farmers, who wish to protect their lambs in winter. |
| D.Microwave heaters cannot be accepted by the public because they are somewhat unsafe. |
People fell in love with Elizabeth Taylor in 1944, when she starred in National Velvet-the story of Velvet Brown, a young girl who wins first place in a famous horse race, At first, the producers of the movie told Taylor that she was too small to play the part of Velvet. However, they waited for her for a few months as she exercised and trained—and added three inches to her height in four months! Her acting in National Velvet is still considered the best by a child actress.
Elizabeth Taylor was born in London in 1932. Her parents, both Americans, had moved there for business reasons. When World War II started, the Taylors moved to Beverly Hills, California, and there Elizabeth started acting in movies. After her success as a child star, Taylor had no trouble moving into adult(成人)roles and won twice for Best Actress: Butterfield 8(1960) and Who’s Afraid of Virginia Woolf ? (1966)
Taylor’s fame(名声)and popularity gave her a lot of power with the movie industry, so she was able to demand very high pay for her movies. In 1963, she received $1 million for her part in Cleopatra—the highest pay r
eceived by any star up to that time.
Elizabeth Taylor is a legend (传奇人物) of our time. Like Velvet Brown in National Velvet, she has been lucky, she has beauty, fame and wealth. But she is also a hard worker. Taylor seldom acts in movies any more. Instead, she puts her time and efforts into her businesses, and into helping others — several years ago, she founded an organization that has raised more than $40 million for research and education. The producers didn’t let Taylor play the part of Velvet at first because they thought she ____.
| A.was small in size | B.was too young |
| C.did not play well enough | D.did not show much interest |
What Elizabeth Taylor and Velvet Brown had in common was that they were both _____.
| A.popular all their lives | B.famous actresses |
| C.suecessful when very young | D.rich and kind-hearted |
Taylor became Best Actress at the age of .
| A.12 | B.28 | C.31 | D.34 |
In her later life , Elizabeth Taylor devoted herself to .
| A.doing business and helping others | B.turning herself into a legend |
| C.collecting money for the poor | D.going about research and education work |
Adult butterflies use their se
nses of sight, touch, hearing, smell, and taste to survive in the world, find food and mates, lay eggs in an appropriate place, migrate, and avoid hungry predators.
Sight
Butterflies have large, compound (multifaceted) eyes, which allow them to see in all directions without turning their heads. Like most insects, butterflies a
re very nearsighted, so they are more attracted to a large stand of flowers rather than individual plants. Butterflies do not "see" colors such as red, green, and yellow, but sense polarized(偏振的) light, which indicates the direction the sun is shining, as well as ultraviolet light, which is present on many flowers and guides butterflies to nectar (花蜜)sources.
Smell
Butterflies have a very well-developed sense of smell, but it's not in their nose (since they don't have one). Sense receptors located in their antennae, feet, and many other parts of the body help butterflies find food (usually flower nectar), and mates (the female smells the male's pheromones).
Taste
Butterfly's feet have sense organs that can taste the sugar in nectar, letting the butterfly know if something is good to eat or not. Some females also taste host plants in order to find appropriate places to lay their eggs. Adult butterflies and moths feed using a probo
scis, a long, coiled tube. Butterflies force blood into the tube to straighten it out, allowing them to feed. Butterflies get all their food from this tube.
Hearing
Butterflies don't have ears. Instead they "hear" sounds through their wings by sensing changes in sound vibrations.
Butterflies may possess senses we don't even know about yet because their anatomy is very different than ours, and therefore difficult to understand when perceived through our own human senses. From the passage we can know that butterflies can see_____
A.thing beh ind them |
B.thing in the distance |
| C.most bright colors | D.flower nectar from a distance |
Butterflies can easily find food resources by using their______.
| A.sense organs of sight and smell | B.sense organs of sight and taste |
| C.sense organs of smell and hearing | D.sense organs of smell and taste |
How do butterflies feed themselves?
| A.by using their feet | B.by using a tube. |
| C.by using sense receptors | D.by using their wings. |
What is the passage mainly about?
| A.The food sources of butterflies. | B.The habits of butterflies. |
| C.The unusual body of butterflies. | D.the sense of butterflies. |
In the long discussion of water on the Moon, a new study contradicts(与……相矛盾)) some recent reports that say the Moon had water at the time of its formation. A group of researchers reported in the journal Science that when the Moon was created, some 4.5 billion years ago, there was not much hydrogen(氢气) on it, and therefore no water.
The researchers surveyed and evaluated this by analyzing chlorine isotopes(氯同位素) found in lunar rock samples from Apollo missions. The range of chlorine isotopes in lunar samples was 25 times that found in samples from Earth.
If the Moon had significant levels of hydrogen, as Earth did, this range would have been far less, said Zachary D Sharp, a scientist in the Department of Earth and Planetary Sciences at the University of new Mexico and the study’s lead authour.
The chlorine would have stuck together with hydrogen, forming compounds like hydrogen chloride, and escaped from the Moon’s surface, he said. The abundance of chlorine indicates a lack of hydrogen and water.
“ The amount of water on the Moon was too low for life to possibly have existed there,” he said.
Most scientists believe the Moon was formed when a large object stuck
Earth, breaking off a chunk(a vast piece) that has since orbited Earth.
On Earth, goes one theory, water was released as steam form molten basalts(玄武岩) over time, eventually forming bodies of water.
“An understading of whether the Moon was dry or wet will help us understand how water appeared on Earth,” Dr Sharp said. A new study indicates that _____ on the moorn.
| A.there is plenty of water | B.water is unlikely to exist |
| C.water existed in the past | D.there is a little water now |
The author would like to tell us ______ through the sixth paragraph.
| A.why there is no water on the Moon | B.how the Moon was formed |
| C.when the Earth struck the Moon | D.where the Moon orbited |
Which is NOT true according to the passage?
A. Zachary D. Sharp, a scientist of New Mexico was in charge of the new study.
B. Chlorine isotopes in lunar samples are 25 time larger than those on the Earth.
C. The more aboundant chloride, the shorter hydrogen and water.
D. The new study is benificial to understand how water appeared on Earth. What can we learn from the passage?
| A.There is enough water on the Earth. |
| B.Hydrogen chloride easily escaped from the Moon’s surface. |
| C.The Earth had significant levels of hydrogen. |
| D.Water on the Earth is directly from molten basalts. |
They leap from helicopters or speeding boats, bringing aid to swimmers who get into trouble off Italy’s popular beaches.
For these dog lifeguards, the doggie paddle (狗刨式游法)does just fine.
These “lifedogs” tow a buoy(救生衣) that victims can grab, or a raft they can sit on to be towed back to
shore, and unlike their human counterparts(与对方地位相当的人), they can easily jump from helicopters and speeding boats to reach swimmers in trouble.
With millions flocking(人群) to Italy’s crowded beaches each summer, the Italian Coast Guard says it rescues about 3,000 people every year — and their dog helpers are credited with saving several lives.
It takes three years for the canines to reach expert rescue status, and currently 300 dogs are fully trained for duty, said Roberto Gasbarri, who co-ordinates the Italian School of Canine Lifeguards program at a centre outside of Rome in the seaside town of Civitavecchia.
“Dogs are useful in containing the physical fatigue(疲劳) of the lifeguard, to increase the speed at which casualties(遇难者) are retrieved(找到并衔回), to increase the security of both the casualty and of the lifeguard,” Gasbarri said.
The Civitavecchia centre is one of a dozen around the country for the school founded more than 20 years ago in the northern province of Bergamo by Ferruccio Pilenga, whose first trainee was his own Newfoundland.
The school will train any breed(品种), as long as they weigh at least 30 kilograms, but Labradors, Newfoundlands and golden retrievers are most commonly used because of their natural instinct for swimming. Each dog works in tandem with(同 ……合作) a human lifeguard, who also acts as the animal’s trainer.Which of the following can act as the best title fo the passage?
| A.Dogs to the Rescue | B.Dogs Are Good at Doggie Paddle |
| C.The Wonderful Performance of Dogs | D.Dogs: Our Loyal Friends |
What advantage do these life-dogs have over human lifeguards in a rescue?
| A.Dog can swim very fast | B.Dogs can finish rescue work with ease. |
| C.Dogs can finish the great work free of charge. | D.Dogs can easily be trained |
Which of the following is TRUE about the Civitavecchia center according to the text?
| A.Any breed can be trained there. |
| B.The ones who have the gift for swimming are welcomed. |
| C.After a better training, the dogs can work alone. |
| D.It is the only place for training dog lifeguards in the school. |
What does the writer want to tell us in the 4th paragraph?
| A.Without the dog lifeguards, 3,000 people would lose their lives every year. |
| B.The buautiful beaches attract millions of people every year. |
| C.Dog lifeguards play an important part in a rescue. |
| D.Italy is a famous place of interest. |