用适当的介词填空

Good measures must be taken to stop some factories ________ harming the environment.

用适当的介词填空

The income of his adds up ________ 1 500 yuan a month.

句型转换

We visited the factory yesterday. The factory produces tractors.

The factory ________ we visited yesterday ________ tractors.

句型转换

He got up early in the morning and he caught the early bus.

He got up ________ early ________ he could catch the early bus.

句型转换

The problem came up at the meeting yesterday. The problem was whether we should put off the sports meeting.

The problem ________ we should put off the sports meeting ________ ________ at the meeting yesterday.

句型转换

Child as he is, he knows a lot.

________ he is a child, he knows a lot.

句型转换

My brother came here so that he could learn English well.

My brother came here ________ study English well.

句型转换

When I walked into the classroom, the lights went out.

When I ________ the classroom, the lights ________ ________ ________.

句型转换

Do you understand what the teacher said just now?

Do you ________ ________ ________ what the teacher said just now?

句型转换

Yesterday I met an old friend in the street by chance.

Yesterday I met an old friend  ________ ________ in the street.