He is（）about his chances of winning a gold medal in the Olympics next year.

A.optimistic

B.optional

C.outstanding

D.obvious

读某区域相关资料图，回答问题。

乙地的气候类型是（）

A.热带稀树草原气候

B.热带雨林气候

C.热带季风气候

D.热带沙漠气候