Unit 5 First aid language points学案（7）

重点句式

1. John was studying in his room when he heard screaming.约翰正在他房里学习，突然听到尖叫声。

本句使用了be doing...when...句式。此句式的意思为"正在......突然......",句中的when相当于and then/and at that time，连接两个并列分句。

☛I was about to go out when someone knocked at the door.

我刚想出门，这时有人敲门。

☛The thief was on the point of putting his hand into the lady's handbag when the bus suddenly stopped.

小偷正要把手伸进那位女士的手提袋中，这时公共汽车突然停了。

☛I had just sat down when the light went out.

我刚坐下，突然灯灭了。

【归纳拓展】

when作并列连词时常用于以下句型中：

Sb. was doing sth. when...某人正在做某事，就在这时......

Sb. was just going to do sth. when...某人正要做某事，就在这时......

Sb. was about to do sth. when...某人正要做某事，就在这时......

Sb. was on the point of doing sth. when...某人正要做某事，就在这时......

Sb. had(just)done sth. when...某人刚做完某事，就在这时......

【跟踪典例】

(1)句型转换

①She was thinking about the problem and at this time Tom patted her.

→She was thinking about the problem ________ Tom patted her.

②The pupils were on the point of listening to the tape and when the teacher came in.

→The pupils ____________________ the tape ________ the teacher came in.

(2)完成句子

①The pupils ________________ the electricity was cut off.