Alan_____in a shop.but he_______there these days.
A,works,isn't working B,is working,works
C,works not works
选A
原因：Alan,第三人称单数,works
根据but,转折,B排除.C 应改为does't work
______are you_______?
Our English teacher.
Who waiting for
原因：who谁
wait for sb固定搭配
The boy in the sea is swimming_____.
A.fast B.happy C.careful
选A happy 和careful为形容词,不能修饰动词
They enjoy_______(live) in BeiJing.
enjoy doing sth,所以填living