—Animals are our friends. We should protect them.—.A. I agree with you.B. Sure go ahead.C

问题补充：

—Animals are our friends. We should protect them.

—.

A. I agree with you.

B. Sure, go ahead.

C. It must fun.

D. How exciting!

答案：

(答案→)A. I agree with you.

B. Sure, go ahead.

C. It must fun.

D. How exciting!

解析：情景交际。I agree with you.我同意你的看法；Sure, go ahead.当然了，继续吧； It must fun.说法错误。How exciting!太令人兴奋了。根据上文，动物使我们的朋友。我们应该保护他们。可知选A最符合语境。