I have read a series of stories about some world famous great scientists, are from our country.
| A．two of them | B．two of whom | C．both of them | D．both of whom |
He was walking along the sands ______ he saw a big footprint in the sand.
| A．while | B．as | C．when | D．after |
In public places, we can often see ______ that tell us useful things, such as no parking, no smoking, etc.
| A．symptoms | B．signs | C．systems | D．signals |
It ______ delicious, so the cake was eaten up and mother smiled.
| A．was tasted | B．tasted | C．was tasting | D．tastes |
The boy is ______ computer games and stays in the Internet cafe all day and night.
| A．interested in | B．enthusiastic about | C．crazy about | D．surprised at |
The government is trying to do something to ______ the employment rate so that more people have jobs.
| A．add | B．gain | C．achieve | D．increase |