Everyone knows that _______ is dangerous to play with fire, but _______ is difficult is to prevent children from playing with fire.
| A．it, it | B．what, what |
| C．it, what | D．what, it |
―Do you have anything to do this afternoon?
―What’s up?
―Let’s go shopping. It’s said that Jinying Shop ______, and all the sweaters are sold at half price.
―Why not?
| A．has closed down | B．was closing down |
| C．closes down | D．is closing down |
Hello. You 68442936. I’m sorry I’m unable to answer your call right now.
| A．reached | B．are reaching | C．have reached | D．had reached |
It seems oil _____from this pipe for some time, we’ll have to take the machine apart to put it right.
| A．had leaked | B．is leaking | C．leaked | D．has been leaking |
—Why were you not at the concert?
—I________ a close game between two European football teams.
| A．watched | B．had watched | C．was watching | D．have been watching |
—Why do you look so worried?
—Fred left the company half an hour ago. His work _______ unfinished since.
| A．left | B．was left | C．has left | D．has been left |