21．When it comes to choosing career, you should first consider type of work which will suit your interest.
A．a; the B．/; a C．the; a D a; /
22．While the dog, I was careless and it was hit by a car.
A. walked B. walking C. to walk D. being walking
23．They are just college graduates and don’t realize ____ to start and run a company.
A. what takes it B. what they take C. what takes them D. what it takes
