人教版英语九上第六单元第一节思维导图

at the bottom of the river在河床底部 be full of the rubbish充满了垃圾

throw litter into the river 把垃圾扔入河中 land pollution 土地污染

play a part in cleaning it up 尽一份力把它清理干净 take action 采取行动

fill the air with black smoke 使空气中充满了黑烟 turn off 关掉

Even the bottom of the river was full of rubbish. 即使河底都充满垃圾

Everyone in town should play a part in cleaning it up.城里的每个人都应当尽一份力把它清理干净

The air is badly polluted because there are too many cars on the road these days

To cut down air pollution, we should take the bus or subway instead of driving.

I used to be able to see stars in the sky. 我过去能在天空中看到星星

The air has become really polluted around here. I’m getting very worried.

No scientific studies have shown that shark fins are good for health.

两者主要区别是时间的参照点不同

过去完成时的时间参照点是某个“过去的”时间；现在完成时的时间参照点是“现在”

因此现在完成时中的很多规则，也适用于过去完成时

When I got to the cinema, the film had been on for five minutes

got 是一个过去的“时间点”，电影“开始”在我“到达”之前，是“过去的过去”

因为 for five minutes 为延续一段的时间状语，应用可延续的系表结构 be on 的过去完成时形式

过去完成时是一个相对的时态，表示的是“过去的过去”，只有在和过去某时或某动作相比较时才用到它

因此当原句中若找不到一个“过去的时间”作为参照点时，是不能用过去完成时的

He got to the railway stationand suddenly realized that hehad forgotten to bring his ticket

It must cost a good deal to live here. 住在这里一定要花很多钱的

take， spend ，cost ，pay 的用法都可以表示“花费”，但用法却不尽相同

spend time ／money on sth. 在..上花费时间（金钱）

I spent two hours on this maths problem. 这道数学题花了我两个小时

spend time ／money （in） doing sth. 花费时间（金钱）做某事

They spent two years （in） building this bridge. 造这座桥花了他们两年时间

pend money for sth. 花钱买..

His money was spent for books. 他的钱用来买书了

sth. costs （sb.） ＋金钱，某物花了（某人）多少钱

A new computercosts a lot of money. 买一台新电脑要花一大笔钱

（doing）sth. costs（sb.）＋时间，某物（做某事）花了（某人）多少时间

Remembering these new words cost him a lot of time.他花了大量时间才记住了这些单词

cost 的过去式及过去分词都是 cost,并且不能用于被动句