He made three good friends in the university, ______ joined the army after graduation.
A. one of them B. one of whom C. one D. one of which
_______ is certain, people’s living conditions in China have improved a lot since the 1980s.
A. It B. As C. what D. Which
Humans are polluting the earth day by day, ________, of course, will cause punishment sooner or later.
A. that B. it C. which D. what
You’d better cut your hair short. Our school doesn’t _______long hair.
A. approve of students wore B. approve students to wear
C. approve of students to wear D. approve of students wearing
—When can we make an appointment with you , sir ?
—What about Wednesday afternoon ?
—OK．_______
A．Do you have time then ? B．It doesn’t suit me．
C．That’s settled． D．It’s so nice to meet you．
The Internet is regarded as one of the reasons_______ many people aren’t getting enough sleep now．
A．which B．what C．as D．why
