11.She hasn‘t decided with ______ she should first make contact.

　　A. who

　　B. whom

　　C. how

　　D. which

　　12.That is ______ we differ.

　　A. that

　　B. where

　　C. what

　　D. whether

　　13.Another worry is that telecommunication systems may isolate people ______ each other.

　　A. from

　　B. for

　　C. with

　　D. to

　　14.If I ______ in your place， I wouldn‘t trouble him.

　　A. were

　　B. had been

　　C. could be

　　D. was to be

　　15._______ the moon moves round the earth is well known to all of us.

　　A. That

　　B. What

　　C. When

　　D. As