In which of the following places can you often see this sign?
| A．In a park. | B．In a school. |
| C．In a science museum. | D．In a street. |
Bicycling is a good exercise;________ it does not pollute the air.
| A．besides | B．beside | C．therefore | D．otherwise |
Please pass me the book ________ cover is green.
| A．which | B．whose | C．that | D．who |
He hurried back home________ his schoolbag.
| A．fetched | B．to fetch | C．fetching | D．fetches |
I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.
| A．couldn’t | B．mustn’t | C．shouldn’t | D．needn’t |
So I rudely replied, “You’ve dialed the wrong number! ” and then ________.
| A．hanged up | B．hung up | C．held on | D．held up |