1.We hoped that they ... this problem
A)will solve
B)solve
C)is solving
D)would solve
2. We hope that they ... this problem
A)will solve
B)solve
C)is solving
D)would solve
3) They say that the ozone layer ... gradually
A)is destr
B)destruct
C)was destructing
D)destructed
4 They say that the ozone layer ... by people's actvies
A)is destructing
B)destruct
C)was destructing
D)destructed