Babiessleepfor16to18hoursinevery24hoursandtheysleeples...

问题详情：

 Babies sleep for 16 to 18 hours in every 24 hours and they sleep less ______ they grow older.

A. while                     B. before                     C. as                        D. after

【回答】

C

知识点：连词

题型：选择题