Ladies and gentlemen, please fasten your seat belts. The plane ____________.
| A．takes off | B．is taking off |
| C．has taken off | D．took off |
the sentence , so he asked the teacher to explain it again.
| A．Not having understood | B．As he didn’t understand |
| C．Having not understood | D．He didn’t understand |
——The weather is too cold ____ March this year.
——It was still ____ when I came here years ago.
| A．for; colder | B．in; cold | C．in; hot | D．for; hotter |
The “Warning” reads: “Under no circumstances _____ be kept near fire!”
| A．the chemical should | B．the chemical shouldn’t |
| C．should the chemical | D．should the chemical not |
Had the boy worked harder, he ______ the exam.
| A．must have got through | B．could get through |
| C．ought to get through | D．would have got through |
________ is surprising to us is that Tom, for _______ English was once boring, can speak English fluently as though he were a native speaker.
| A．As; whom | B．What; whose | C．It; whose | D．What; whom |