–Mr Smith, I don’t think we can get there on time by bike.

–You mean it’s ______ for us to take a taxi?

A. necessary　　　 B. important　　　 C. possible　　　 D. difficult

—What are you doing?

—I’m ________ TV.

A. watching　　　　　 B. watches　　　　　　　 C. watched

--How do you study for a test?

-- _____ working with friends.

　　　 A. By　　　　　　 B. With　　　　　　　 C. On

-- I hope you don't mind my opening the window.

-- ______ It's much too hot in here.

　　 A. Certainly　　　　　 B. Of course not

　　 C. All right　　　　　 D. Never mind

Take the exam carefully, _____ you won’t get full marks.

A. but　　 B. and　　 C. or　　 D. so