Of the following, the expression “( )" is an idiom.

Of the following, the expression “( )" is an idiom.
A、feet service
B、hair service
C、teeth service
D、lip service
【正确答案】：D
【题目解析】：选项中只有lip service 为习语，意思为“空口的应酬话，表面文章”。故D选项符合题意。