Ⅰ.单句语法填空
1．________ moment he thought of his lost son, he burst into tears.
2．Though it has been one year ________ he came to the city, he knows every street here like the back of his hand.
3．________ people are depressed, they tend to withdraw and don't have the motivation and energy to go out and do things.
4．When ________ (ask) for his views about his teaching job, Philip said he found it very interesting and rewarding.
5．—Have you got any particular plans for the coming holiday?
—Yes, ________ possible, I'm going to visit some homes for the old in the city.
