If you are in trouble，Mike is always willing to________a hand.           

Tom asked the candy makers if they could make the chocolate easier ______ into small pieces.

After staying in room for weeks, the lady was advised to go to the outside world to ______ her confidence as well as health. 

We all       goodbye to my father as he was on the train to Beijing．

It’s hot in the shopping mall, because the air-conditioning system ______.