）Why ______ ask your mother to shop with you.
| A．not you | B．don’t you | C．not to | D．won’t you |
--When _____ the abacus _____? -- In the sixth century by the Chinese people.
| A．is, invented | B．did, invent |
| C．was, invented | D．does, invent |
We have been friends for nearly twenty years. Nothing can break off our _______.
| A．friendship | B．pleasure |
| C．decision | D．experience |
In our city, ________ college students want to work as a teacher in holidays.
| A．thousand |
| B．thousands of |
| C．thousand of |
| D．two thousand of |
I don’t like eating chocolate. The taste is too ________.
| A．crispy | B．delicious |
| C．salty | D．sweet |
-- Look at the boy running on the ground. Is it David?
-- It _______ be him. I saw him go to the teacher’s office just now.
| A．might | B．could |
| C．can’t | D．mustn’t |