— I think you'd better type this letter again before Mr. Smith see it.

— Oh, dear! _____ [ ]

A. Who cares?

B. No problem

C. I don't mind at all

D. Is it as bad as that?

保护生物多样性最为有效的措施是  （   ）

A．迁出原地保护

B．建立植物的种子库、动物的精子库

C．建立自然保护区，实行就地保护

D．禁止一切形式的采猎和买卖珍稀动、植物