We must tell people ____ important it is to protect our lakes(湖泊), rivers, seas and oceans(海洋).

A. what                      B. very                       C. how                       D. too

We must tell people ________ important it is to protect our lakes（湖泊）, rivers, seas and oceans（海洋）.

1. A.
   what
2. B.
   very
3. C.
   how
4. D.
   too