Keepingaregularsleepscheduleisimportantforsettingababy’...

問題詳情：

Keeping a regular sleep schedule is important for setting a baby’s  body

clock ,        researchers   note should be in place by about 4 months of age.

A.  whose   B.  which   C.  when  e

【回答】

B

知識點：連詞

題型：選擇題