--Are Mr and Mrs Wang living alone in the house?---Yes, they have three sons, but______of the sons live with them.
—________is the river? —It’s about 5 meters in depth.
The man is confident of himself when he is________the face of difficulties.
I can see some children________basketball in the playground now.
The boy was badly ill.He had to drop out of school because of________.
We shouldn’t________he trees in order to protect the environment.