1.It is often the case _______ anything is possible for those who hang on to hope.

A. why                  B. what             C. that             D. as

2.Not until recently _______ the development of tourist-related activities in the rural areas.

A. they had encouraged                       B. had they encouraged

C. they encouraged                           D. did they encourage

3. Many businesses started up by college students have _______ thanks to the comfortable climate for business creation.

A. fallen off                B. turned off           C. taken off            D. left off

4. Parents should actively urge their children to _______ the opportunity to join sports teams.

A. gain admission to    B. keep track of        C. give rise to     D. take advantage of