— Alvin，are you coming with us?
—I'd love to，but something unexpected ________.
| A．has come up | B．was coming up |
| C．had come up | D．would come up |
It was not until this year _____ scientists managed to make a cat and a goldfish disappear from sight using an invisibility cloak(斗篷)
| A．that | B．when | C．while | D．As |
The comedy actor, _____ only 55 kilos but ____ in a heavy oversized coat , looked funny enough to make all the audience laugh.
| A．weighed; dressed | B．weighed; dressing |
| C．weighing; dressed | D．weighing; dressing |
______ bright a talker you are, there are time when it’s better to remain silent.
| A．Whatever | B．However | C．Whenever | D．Whoever |
—Have your read the article A Dirty Beijing, which is about air pollution?
—Yes. It’s highly informative. I _____no idea that the PM2.5 there sometimes reached 300.
| A．have | B．had | C．will have | D．would have |
—What do you think of being a volunteer, John?
—I find it a stressful job but one ___ you can really help people.
| A．where | B．which | C．when | D．that |