In some western countries， some people don't like the number 13 because they think 13 is an unlucky number． For example， they don't like to live on the thirteenth floor． One evening， Mr． Smith asked some friends to get （1）t ogether ． When all of his friends arrived， he asked them to sit at the table for （2）d inner ． He began to （3）c ount the people． Suddenly， he cried out ， " Oh， there are thirteen people here! " Everyone's face looked pale （4）e xcept Mr． Brown． He said with a smile ， " Don't worry， my friends． My wife will have a baby in a few weeks． So we have （5）f ourteen people here． " All of the friends became happy again． " Congratulations ! " they said to Mr． Brown． They all had a good time that evening．
Zu Chongzhi was one of the greatest mathematicians（数学家） in ancient China.He was born during the Northern and Southern（1） （ dynasty）.From a young age，Zu was taught natural science，astronomy（天文学），math and so on.The little boy was （2） （ interest） in all of these subjects，especially in （3） .
Zu was best known for his calculation（计算） of pi （π）.According to the record，he did all the work using nothing but wooden sticks. （4） took him lots of time to work out the value —（5） 3.1415926 and 3.1415927.No one at that time was able to do better than Zu.And now the achievement is still praised by people around the world.In order to remember Zu，some mathematicians suggest （6） （call） pi"Zu Lv".
Zu was successful not only in math，but also in astronomy.He worked out that a year should be 365.24281481 days long and created the Daming Calendar. （7） ，government officials at that time did not agree with Zu.The great mathematician （8） saw his calendar put into use.Almost ten years after his （9） （die），the new calendar was finally accepted.
Zu was an inventor，too.He once made a vehicle（车辆） （10） carried a pointer （指针）.No matter how the vehicle turned，the pointer always pointed to the south.
Bicycle riding is good exercise.It helps people become （1）f .Bicycle riding can make the riders' hearts and lungs strong.It is also good for the environment because bicycles do not cause （2） （污染）.
Bicycles share the road with cars and trucks.Drivers do not always notice bicycles.So bicycle riders must （3）p attention to the traffic around them and know traffic signals.They must know and obey the safety （4）r .They must wear helmets to protect their heads.If they ride at night，they should have lights on the bicycle or wear light﹣colored clothes.In case of an accident，bicycle riders should know how to give first aid.If an injury is serious，they must call 120 for help.In a word，the best way to be safe is to be （5） （小心的）.
When we say "we threw something out，" what do we really mean？After all，our waste doesn't just disappear even if it is taken a（1） .So why not recycle it？
Have you ever used newspapers when you clean the windows？If you haven't，please try!I didn't believe it when I（2） （听到）and read that.I thought that they would certainly leave ink（墨汁）or bits of paper behind.Actually，I was so wrong.I have had clearer windows than before s（3） I tried it
When we mention cleaning products，we have to talk about paper towels（手巾）I used （4） to think more paper towels meant a cleaner home.I loved the idea of cleaning with the fresh white paper and then throwing（5） out.But now I know that I have to s（6） using paper towels，because paper towels are a huge waste problem.Cutting out paper towels would save（7） （树），water，air and our money.
Recently.my family and I have started collecting all old （8） （衣服），and then cut them into pieces.Getting one piece to do some cleaning has become our n（9） habit.I thought that it would be such（10） uneasy thing to break a 30﹣year old habit.Whatever，it really is the most meaningful thing that I have done during a long time.
阅读下面短文，在空白处填入适当的内容（1个单词）或括号内单词的正确形式（不超过3个单词）。
Tea is the leaf of a plant which grows widely in China.It is our national drink and tea﹣drinking is one of the daily activities of Chinese people.In China， （1） a visitor comes，he is served with a cup of tea.
Tea﹣drinking has （2） history of over 4，000 years.According to Tea Classics by Lu Yu，tea was discovered by Shen Nong，and became a drink in the State of Lu because of Zhou Gong.According to a legend，Shen Nong tasted hundreds of wild plants （3） （stop） people from eating poisonous （有毒的） plants.One day，he was poisoned by an unknown plant but （4） （save） by eating leaves of an evergreen plant.Later，people called the leaves that saved his life "Cha （tea）".
Drinking tea does good to people in many ways.When people are tired，they feel better after drinking a cup of tea.Compared with people who don't drink tea，tea drinkers are likely to enjoy a （5） （long） life.It is said that drinking tea can also help fat people lose weight.
In an old building in Peking University，a yellow light shone into the old and dark hours of the night.The famous translator Xu Yuanchong （1） （sit） behind the window and staring at the computer screen.He enjoyed working by （2） （he） from 10：00 p.m.to 4：00 a.m.For him，the quiet night was a（3） （value） time to focus on translation.He was exploring how （4） （spread） Chinese culture abroad by translating Chinese beauty into Western beauty.
Xu was born into a literary family in Nanchang （5） April 18th，1921.When he was little，he （6） （influence） by his mother who was interested in literature.Xu began to translate Chinese poetry into both English and（7） （France） when he was still a teenager.He soon learned that Chinese and European languages were very different.Only about half of the words in these languages could be translated word﹣for﹣word.This is why translators should have （8） creative mind.They are always trying to improve their translations to make sure they are correct and beautiful.
Xu's motto is：Good，better，best.Never let it rest.Until your good is better，you're your better best.（9） Xu was widely considered to be the best，he never stopped trying to become better.The more you learn and the （10） （hard） you study，the better you will become.There is always room for improvement.