They discovered the cause of the fire accidentally. They discovered it _______.
| A．fortunately | B．by chance | C．all of a sudden | D．on purpose |
—May I have another chocolate?
—Yes, of course.___________.
| A．Take it yourself | B．Eat it, please |
| C．Help yourself | D．Have it yourself |
Shortly after the accident, two___________ police were sent to the spot to keep order.
| A．dozens of | B．dozens | C．dozen of | D．dozen |
My dictionary__________. I have looked for it everywhere but still
| A．has lost;do not find | B．is missing;do not find |
| C．has lost;have not found | D．is missing;have not found |
—Who has taken my pen away?
—__________. He was here a moment ago.
| A．It must be Li Ping | B．It is Li Ping take |
| C．Li Ping is | D．Li Ping must take |
____________professional violinist practices for several hours a day, but____________ violinist has his own way of playing the Beethoven concert.
| A．Each, every | B．Every, each | C．One, a | D．All, each |