如图，正六边形ABCDEF中，$\overrightarrow{BA}+\overrightarrow{CD}+\overrightarrow{EF}=$  (      )

如图中画出了光线通过透镜（图中未画出）的情形，其中凸透镜是（　　）

读图，回答下列问题。

D：What's wrong with you?

P：____

D：____

P：Since last night．

D：Have you had breakfast?

P：No，I don't want to eat anything．

D：____(5 minutes later)

  OK．open your mouth and say“Ah…"

P：Ah… ____

D：Nothing serious．Just a cold．____Have a good rest and drink more water．You'll feel better soon．

P：OK，thank you，doctor．