The elderly good care of in public places like supermarkets and airports; they are likely

问题补充：

The elderly good care of in public places like supermarkets and airports; they are likely to get lost.

A. can have been taken

B. ought to be taking

C. must be taken

D. should take

答案：

A. can have been taken

B. ought to be taking

(答案→)C. must be taken

D. should take

解析：词义辨析。主语The elderly和take good care of是动宾关系，要用被动形式，排除B,D；can have been taken，可能已经被照顾；must be taken必须被照顾。句意：老人在公共场所，例如超市和机场，必须被好好照顾；他们很可能会迷路。所以选C。