---- You should be _______ careful when you take the chemistry exam.
---- I agree. In this way, I will make _______ mistakes.
| A．more; less | B．more; more |
| C．more; fewer | D．less; fewer |
— _____ you stay in America every summer?
—For two months.
| A．How many | B．How often |
| C．How long | D．How |
Mary isgirl, but she knows a lot about science.
| A．a eight-year-old | B．eight-year-old |
| C．eight years old | D．an eight-year-old |
Find the answer _____ the question, please.
| A．of | B．with | C．to | D．for |
It is a good time _____.
| A．sing | B．to sing | C．singing | D．sang |
They each _____ a CD in their bags.
| A．have | B．has | C．is | D．are |