The porter (saw) that we were comfortably settled in our seats.

问题描述:

The porter (saw) that we were comfortably settled in our seats.
A.observed
B.looked at
C.made sure
D.be sure
为什麼答案选C
A,B的意思都跟题目(saw)一样啊

A是观察(如星空,植物长势等科学观察)
B意为目不转睛盯着
D主语只能是第一人称