_______the activities might seem childish, in reality they require a lot of strength and determination.
| A．When | B．As | C．While | D．Once |
It is a paradox（自相矛盾） that ina rich country there should bemany poor people.
| A．such; such | B．such; so | C．so; so | D．so; such |
We are living in an agemany things are done on computer．
| A．which | B．that | C．whose | D．when |
Although knocked down by a car, he managed to ______ to his feet.
| A．stand | B．rise | C．run | D．struggle |
The sun heats the earth, ___________ is very important to living things.
| A．that | B．what | C．which | D．where |
I will visit you if Father ______ me.
| A．let | B．lets | C．is letting | D．will let |