How _____ you say that you have made great progress since there are so many mistakes in your test paper ?

A．can

B．must

C．need

D．may

人类生态环境保护的道德原则包括（）

A.尊重自然的道德原则

B.合理利用资源的道德原则

C.系统综合的道德原则

D.同步效应的道德原则

E.面向未来的道德原则