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