问一道英语单选题,请解释下原因,
问题描述：
问一道英语单选题,请解释下原因,
The security of the babies is supposed to ___ by the nurses.
A.see to B.be seen to
C.be seeing to D.be seen
答
1. be supposed to do sth. 应该做某事
2. 小孩是被照顾的,所以用被动语态,所以排除 A,C
3. see to sb./sth.负责,照顾,注意
综上所述,选B