—I can't decide__________.

—You mean the purple sweater or the blue one?[ ]

A. how to go there    

B. who to go with

C. where to visit      

D. which to choose

夏季气温过高，发动机易过热，应注意检查冷却系的密封情况和散热效果，防止汽车（）下降。

A.转速

B.扭矩

C.动力性

D.制动性