1. _______ her address, we couldn’t get in touch with her.

　　A. Not to know B. Having been known

　　C. Not knowing D. Not been known

　　2. _______ nature reserves ________ us learn more about protecting animals.

　　A. Studying; help B. Studies; helps

　　C. To study; helping D. Studying; helps

　　3. The program, _______ at the meeting yesterday, was about the development of our city.

　　A. discussing B. having discussed

　　C. to be discussed D. discussed

　　4. I tried to make the girl _______ by singing and that worked well in the end.

　　A. to stop to sleep B. to stop sleeping

　　C. stop to sleep D. stop sleeping

　　5. _______, a man who express himself effectively is sure to succeed more rapidly than a man whose command of language is poor.

　　A. Were other things equal B. Other things to be equal

　　C. Other things being equal D. Being equal to other things