1.— What about the protection of these new machines?

— Let's keep the surface ________ dust by putting a cover over them.

A. far from                         B. apart from                         C. free from                         D. away from

2.It's required that the football match _____ put off ___ the bad weather.           

A. be; because of             B. would be; due to             C. was; thanks to             D. was; owing to

3.— Do you know _________ made him successful in his career? 

— Yes. His hard work and strong will, of course.

A. what it was that           B. what was it that           C. it was what that           D. was it what that

4.Who is the student our English teacher ________ the spelling?

A. had checked                     B. had check                     C. got checked                     D. got check