Some people have the idea_____ you can cross Canada in less than five days.

A. what             B. that                 C. which                 D. when

 Only after her mother came to help her for the first few months ______ to begin her project.

A. did she allow            B. had she allowed   

C. was she allowed          D. is she allowed

 Thanks to Dr Yuan’s research, the UN has more tools in the battle to rid the world _____ hunger.

     A. of      B. on     C. off      D. at

 ______ is even more important is that the earth cooled down, water began to appear on its surface.

A. When    B. That     C. Which     D. What

 Jane _____ these families of chimps for many years and helped people understand how much they behave like humans.

A. had studied     B. studied                     C. studies            D. has studied

 It is so wet there _____ the trees are extremely tall, some measuring over 90 meters.

     A. what     B. which     C. that      D. why        

 Many _______ of years later, the first extremely small plants began to appear on the surface of the water.

     A. millions    B. million     C. million of     D. millions of

 _______ Jane’s way of studying chimps, our group are all going to visit them in the forest.

A. Follow    B. Following    C. Followed    D. To follow

Jane warns us that our group is going to be very tired and dirty by the afternoon and she is right. However, the evening makes it all ______.

A. favorable　　　 B. worthwhile　　 C. precious　　　 D essential

 Many of them have ______ gift for riding wild horse and can win thousands of dollars in prize.

A. /      B. an      C. a       D. the