----Look at the boy running on the playground. Is it David?
---- It ______ be him. I saw him go to the teachers’ office just now.
| A．mustn’t | B．can’t | C．may not | D．needn’t |
—The population of the world ____ still ____ now.
—So it is.
A. are; growing B. will; grow C. is; growing
—It smells terrible. What has happened here?
—Look, there is a chemical factory_____ much waste gas.
A. pour B. pouring C. poured
In our class _____ of the students _____ girls.
A. two fifths; are B. second fifth; are C. two fifths; is
—Where are Maria and Kangkang?
—They _____ England.
A. had been in B. have gone to C. have been to
—I’ve_____the bike_____a year.
—Is it still new?
A. had,for B. bought,for C. had,since