I ran across a car crash in Hong Kong, and ________, both sides just politely exchanged the telephone numbers and cards, a surprise to me.

The girl seriously injured in the Wenchuan earthquake was so well taken care of in the hospital that she could ____ get out of bed without help．

He began to take political science        only when he left school.

Trees need water to grow; _____, friendship needs our heart and passion to develop.

 I can't believe what he says because he is _______ changing his mind. .