He sometimes ___________ a train to work.
During the charity walk, people have to walk_____ country parks and_____ hills and mountains.
All the children should be helped when they are ______. They should also be treated with ______.
The old man is ______ weak ______ say any words.
We should try our best _______ poor children _______ clean water and food.
You’d better go out for a walk instead of _______ in your bed.