Through the open window we saw on the floor the happy father lying ________ his stomach, his daughter riding excitedly on his back.

A. on　　　　 B. with　　　　　　 C. above　　　　　 D. from

—I bet someone stole my backpack.

—Well，you________have kept an eye on it.

A．may 　　　　　 B．can　　　　　　 C．would 　　　　　D．should

By the time Einstein was 14 years old, he_______ himself advanced mathematics.

A. has taught　 B. taught

C. had taught　　 D. was teaching

　　　 they decide which college to go to, students should research the admission procedures.

　　 A. As　　　　　 B. While　　 C. Until　　　　 D. Once

What I need is_____ book that contains ______ABC of oil painting. 
 A. a; 不填        B. the; 不填     C. the; an     D. a ; the

ara had _________ the disadvantages of her background and became a successful lawyer at last .

A. recognized　 B. struggled　　　 C. prevented　　 D. overcome

Do you know the year ______the Chinese Communist Party was founded?

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

David jumped _____ to get the first ______ the beginning of the sports.

A. enough high; in 　 B. enough highly; in

C. high enough; at 　 D. highly enough; at

Can you tell me the date________ the accident happened？?

A.on which　　　　　 B.that ?　　　　　　 C.on when　　　　　 D.in which