Điền vế câu thích hợp: It is necessary that..

1. It is necessary that...

A. We may protect the environment
B. Should protect the environment
C. We should protect the environment

D. We should protect environment

2. We should suggest...
A. That the company should keep the  water clean

B. The company keeps the  water clean

C. That the company should keep  water clean

D. The company keep the  water clean

3. Since your house isn't far from the school,...
A. You should go to school
B. You should walk to school

C. You should walk school

D. You should walk