If only I _____ a few days ago！Then I wouldn’t have been feeling so worried now.

A．looked ahead

B．could look ahead

C．were to look ahead

D．had looked ahead

打开无菌溶液需检查核对的内容有（）。

A.瓶签

B.使用有效期

C.瓶盖有无松动

D.瓶口有无裂缝

E.溶液有无沉淀、浑浊、变色