If you meet trouble, you can ______ your friends ________ help.
A lot of trees ______ in the country every year.
_____ he is only 4 years old,he is able to play the piano very well.
Working hard ________ the key _________ success of everything.
We feel like ___________ the work as soon as possible.
The old man lives _______ in the countryside, but he didn’t feel __________.