29、The scientists are trying to find out what ______ caused the dolphins to strand themselves, a strange animal behavior hard to understand.

     A. was it that            B. that was that    C. was that which      D. it was that

28、The government has revised the budget, 5% of______ will be used to help develop the medium  and small sized enterprises.

     A. that                  B. whose        C. which            D. as

27、You may depend on ____that your parents will help you whenever you need it.

A. them        B. yourself        C. it              D. me

26、Unlike watching TV, reading is a highly active process _____ it requires attention as well as memory and imagination.

A. until        B. bit            C. unless          D. for

25、When he was retired and went back home in _____, he was already in______.

A. the fifties; his sixty              B. fifties; his sixties

C. the fifties; his sixties            D. fifty; sixty

24、---He ought to have been warned of the danger.

---_______but he wouldn’t listen to me.

A. He did       B. He should      C. He ought to     D. He was

23、 ---Would you like to have a cigarette?

---No, thanks. It is three years since I _______.

A. have begun to smoke           B. smoked

C. began to not smoke             D. had smoked

22、I tried to get through to her, but she simply ___ not turn on her cellphone as she was busy.

A. could        B. might        C. would           D. should

21、Li Rong told me what difficulty she had have_____ English before she came to Canada.

A. learning      B. learn         C. learnt           D. to learn

20、Among almost seven hundred kinds of bamboo, some fully grow___ a foot, while others can grow three feet.

A. as high as    B. higher than    C. no higher than    D. so high as