Today, we’ll discuss a number of cases ____ parents have much difficulty in communicatingwith their children[ ]

Mary clapped her hand over her mouth_______ she realized what she had said

Yesterday a thief_________ the bank and helped himself to millions of money.

(2014·山东实验中学二模)You can never be________careful，the road is icy and slippery

You’d better put things back.Otherwise, it will be difficult to find things.[ ]