B. for
D. electricity
C. from
C. so that
A. doesn't study
D. and
B. and

1. B. for
   Green forests provide more spaces for animals and birds.

2. D. electricity
   Turning off the air conditioner ten minutes before leaving saves a lot of electricity.

3. C. from
   Governments should prevent people from cutting down trees in the forests.

4. C. so that
   People shouldn't use plastic bags so that they can reduce land pollution.

5. A. doesn't study
   She won't pass the exam if she doesn't study hard.

6. D. and
   Barry loves running. And he is also a member of our school's running club.

7. B. and
   We should always remember 3 Rs to protect the environment, "Reduce, Reuse and Recycle."