Theyrecommendedthatadultsuseheadsetsorspeakerphonesand...

問題詳情：

 They recommended that adults use headsets or speaker phones and _______ children and teens, whose brains tissues are still developing, use cell phones only for emergencies.

A. that                           B. /                              C. while                       D. what

【回答】

A

知識點：連詞

題型：選擇題