中考化学知识点之氢氧化钠物理性质
氢氧化钠、氢氧化钙的物理性质、用途 ...
【重点词汇、短语】
1. struggle 斗争
2. expand 使变大,伸展
3. thanks to 幸亏,由于
4. rid 摆脱
5. rid…of 摆脱,除去
6. be satisfied with 对…感到满意
7. would rather宁愿
8. therefore 因此
9. export 出口
10. regret 后悔,遗憾
11. build up 逐渐增加,建立,开发
12. lead to 导致
13. focus on 集中与
14. reduce 减少
15. keep...free from/of 使…免受影响
16. comment 评论,议论
【重点句型】
1. Have you ever grown any plants? If so, what did you do to grow them? If not, what kind of plant would you like to try growing?你种过植物吗?如果种过的话,你是怎么种植的?如果没有种过的话,你想要尝试种植什么植物?△ If so为省略句式,意为“如果是这样的话”,if用作连词,so 用来代替上文的内容,以避免重复。If not 意为“如果不是这样的话,否则,要不然”,意义与If so 相反。
2. In 1974, he became the first agricultural pioneer in the world to grow rice that has a high output.1974年,他成了世界上第一位种植高产水稻的农业先锋。△不定式放在表示次序的词如the first, the last以及the only, the very, the right, the best等词后面作定语,且与所修饰的名词之间构成逻辑上的主谓关系。
3. Using his hybrid rice, framers are producing harvest twice as large as before. 用他的杂交水稻, 农民种出的粮食是以前的两倍。△“…times as+形容词/副词的原级+ as”为常见的倍数表达法,意为“是……的几倍”。This room is three times as big as that one.这个房间是那个房间的三倍大。知识拓展英语中常见的倍数表达法还有:This room is twice bigger than that one.= This room is three times the size of that one.这个房间是那个房间的三倍大。The output of TV sets in our factory is 15 times that of ten years ago.= The output …is 15 times what it was ten years ago.我们厂电视机的产量是10年前的15倍。
【语法总结】
动名词
动词的ing形式如果是名词,这种形式叫做动名词。动名词具有名词的性质,因此在句中可以作主语、表语、宾语、定语等。
一. 动名词的四种形式及其意义
①基本形式:doing (表示主动)②被动式:being done(表示被动)③完成式:having done(表示主动和完成)④完成被动式:having been done(表示被动和完成)
例如:Travelling in space by ordinary people will be common in the future.在未来,普通人在太空旅行将会是普遍的事情。
Freddy and his band could go nowhere without being followed by their fans.Freddy和他的乐队到哪里都被他们的粉丝跟着。
I have no idea of his having done such a thing against you.我不知道他做过这样一件违背你的事情。
Many customers complain of having been given short weight at that shop.很多顾客抱怨在那家商店被缺斤少两过。
二. 动名词的语法功能
动名词在句中可以做主语、宾语、表语和定语等。
Learning English is very difficult .(作主语)学英语非常困难。
I enjoy dancing.(作动词宾语)我喜欢跳舞。
I have got used to living in the country.(作介词宾语)我已经习惯了住农村。
His job is driving a bus.(作表语)他的工作是开车。
The washing mashine woks well.(作定语)这台洗衣机非常好用。
三. 注意事项
1. 只接动名词(不能接不定式)作宾语的28个常用动词
practice、consider、enjoy、finish、give up、imagine、keep、put off、risk、suggest、admit、advise、allow、appreciate、avoid、delay、deny、discuss、dislike、escape、excuse、fancy、forbid、mention、 mind、miss、permit、prohibit
2. 既可接不定式也可接动名词,但含义完全不同的8个动词
remember to do sth. 记住要做某事(未做) remember doing sth. 记得做过某事(已做)
forget to do sth. 忘记去做某事(未做)
forget doing sth. 忘记做过某事(已做)
regret to do sth. 遗憾要做某事(未做) regret doing sth. 后悔/抱歉做过某事(已做)
try to do sth. 努力做某事
try doing sth. 尝试做某事
mean to do sth. 计划做某事
mean doing sth. 意味着做某事
can’t help to do sth. 不能帮助做某事 can’t help doing sth. 情不自禁做某事
go on to do sth. 继续做另一件事
go on doing sth. 继续做同一件事
stop to do sth. 停下来去做另一件事stop doing sth. 停下正在做的事情
3. it 做形式主语,动名词做真正主语位于句末的重要句型
It is no use/not any use/hardly any use/useless doingIt is no good / not much good doing It is no worthwhile doing It is a waste of time doing