Fully ________ in looking after three children at home, she no longer has time to enjoy   various activities in the club.

A．attached

B．occupied

C．contributed

D．devoted

孩子在学习、成长中难免有困惑或者不满，但又不能充分地表达出来，这时家长就要注意（）的使用，尽量找孩子谈谈。

A.霍桑效应

B.增减效应

C.蝴蝶效应

D.登门槛效应