I failed in the spoken examination last term and only then _______ the importance of practicing speaking English.

A. I had realized    B. had I realized      C. I did realize   D. did I realize

—He was downloading reading materials from a website when the computer crashed.

—_______ that he looked a little upset.

    A. No doubt         B. No use           C. No wonder        D. No problem

Whitney Houston was confirmed dead in her LA hotel room, _____ a tragic(悲剧的) end to the world’s most popular singer.

A. marked           B. to mark              C. having marked    D. marking

To our relief, Xiaodan as well as the other children who ______ no parents ______ good care of in the welfare institute.

A. have; is being taken                 B. has; are being taken 

C. has; is being taken                  D. have; are being taken

_______ in a poor family made Yuan Longping determined to solve the hunger problem in China when he was still young.

A. Bringing up      B. Being brought up   C. Having brought up    D. Brought up

—I think the whole class is going on a field trip next Friday.

—I’m not sure. ____________ has paid the transportation fee.

A. Not everyone      B. No one              C. None of them    D. Neither of us

Mrs. Obama introduced the Let’s Move _______ yesterday. Its goal is to reduce children obesity(肥胖) today and in the future.

A. challenge       B. battle               C. campaign       D. behavior 

__________ her son for half a month, Marcia decided to leave for Texas with the hope of finding him.

A. Not heard from               B. Having not heard from  

C. Not to hear from             D. Not having heard from

According to the statistics, listening to loud music at rock concerts ______ hearing loss in some teenagers in the past 2 decades.

A. have caused        B. caused         C. had caused           D. has caused

One way to ______ species under threat of extinction is to remove them to zoos and parks and feed them there.

A. reserve          B. prevent          C. preserve         D. reduce