Scientists think they have _____ in their attempt to find the causes of some major dieases.
| A．broken through | B．worked out | C．fallen out | D．got round |
The audience waited until the curtain rose and then ____ laughter at the sight of the funny actor.
| A．burst out | B．burst into |
| C．broke into | D．began with |
—A number of people ________ learning English nowadays.
—Yes. The number of people who are learning English ________ increasing.
| A．is; is | B．are; are |
| C．are; is | D．is; are |
Our manager is so ________that she won't change her mind, so we have to change our plan.
| A．reliable | B．stubborn |
| C．patient | D．careless |
I said hello to you in the street yesterday, but you ________ me completely.
—I'm sorry. Maybe I didn't notice you.
| A．cheated | B．hid |
| C．ignored | D．recognized |
petrol
| A．fluent | B．destroy | C．prefer | D．spelling |