ing 形式的用法

用法 例句

时间 Walking along the street, I met Mary. (=While I was walking along the

street。。)在街上走的时候，我遇到了玛丽。

原因 Being tired, I stopped to take a rest.(= Because I was tired, ….)因为疲倦，我停下

来休息。

条件 Turning to the left, you will find the school. (= If you turn to the left, ….)向左走，

你就会找到那个学校。

让步 Knowing where I live, he never come to see me .

(= Though he knows where I live, ….) 尽管他知道我的住处，但从不来看我。

伴随 I stood there, waiting for her. (= …, and waited for her.) 我站在那儿等她。

结果 It rained heavily, causing severe flooding in the area.(= It rained heavily so that it

caused severe flooding in the area.)在这个地方雨下的如此大，以至引发了洪灾。

2. –ing形式的完成式 句型

主动 Having +p.p. …, 主语+谓语

被动 (Having been) +p.p. …, 主语+谓语 用法

• –ing形式的完成式所表示的时间在谓语动词之前 • 表示被动可直接用过去分词 例句

Having finished my work, I went home. (= After I had finished my work, ….)工作做完之后，我就回家了。

(Having been) written in haste, the book has some faults. 这本书因仓促写成，所以有些缺憾。 3. 使用- ing形式作状语时需注意的几个问题。

1.分词 (短语) 作状语时, 其逻辑主语必须与句子的主语一致。如果不一致，必须用独立主格结构来表示，也就是在分词前面加上它的逻辑主语。

My wife had a long talk with Sally, explaining why she didn’t want the children to play together. 我妻子与莎莉谈了很长时间, 解释她为什么不想让孩子们在一起玩。

(现在分词explaining是句子主语my wife做的动作,它们之间是主动关系, 即explaining的逻辑主语，就是句子的主语my wife 。)

The train having gone, we had to wait another day.（the train逻辑主语 + having gone 即为独立主格结构）

2.分词短语做状语时，前面可以加上连词或介词，但是分词短语和句子之间不能用并列连词(如but，and)，因为并列连词接的是两个并列成分，而分词短语只是全句的一个状语部分，分词和主句之间可用逗号。 例如:

误: Having been told many times, but he still couldn’t understand it. 正: He was told many times, but he still couldn’t understand it. Having been told many times, he still couldn’t understand it. 但： While walking along the street, I met Mary.

3.-ing的一般式和完成式都可以表示先后接连发生的动作。在可能引起误解的场合应该用完成式表示先发生的动作。 例如:

Opening the drawer，he took out his wallet. (=He opened the drawer and took out his wallet.) 他打开抽屉，拿出钱包。

Coming into the room, he put down his bag. (=He came into the room and put down his bag.) 他走进房间，放下提包。

Having brushed his teeth, Mr. Brown came downstairs for breakfast. 布朗先生刷过牙, 就下楼来吃早饭。

(此句如写成: Brushing his teeth, Mr. Brown came downstairs for breakfast. 可能指 “边刷牙, 边下楼 。)

分词的否定形式是在分词短语前面加上 not, never等否定词构成。 例如:

Not fearing the fire, the child touched

and got a finger burnt. 小孩儿不知道 怕火，用手去摸，把手指烫了。 Not knowing how to find the subway,

I asked a policeman for help. 我不知怎样找到地铁，就去找警察帮忙。 (2)作宾语 下列动词(组)只能接动名词作宾语

admit, advise, allow, appreciate, avoid, consider, delay, enjoy, escape, excuse, finish, imagine, mind,miss,quit,pardon, permit, practise, suggest, require, be (get) used to(习惯于...), cant’t help(禁不住), feel like, set about,

keep on, look forward to, devote oneself to, insist on, pay attention to, be worth, give up, put off。 下列动词后跟不定式或动名词意义区别不大： begin, start, love, continue, hate, prefer。

下列动词后跟不定式或动名词意义不同，在平时学习中应特别注意。 forget, remember, regret, try, stop, mean, go on, can't help。

下列动词后跟动名词主动语态，不定式被动语态作宾语表示被动。 need, want, require

如：These clothes need mending (to be mended).

影响电离平衡有哪些因素

浓度：a.加水稀释：正向移动，电离程度增大。b.增大浓度：正向移动，电离程度减小 温度：电离吸热，升高温度，平衡正向移动

同离子效应：同离子效应(即在弱电解质溶液中加入同弱电解质具有相同离子的强电解质，使电离平衡向逆方向移动) 化学反应：在弱电解质溶液中加入能与弱电解质电离产生的某种离子反应的物质时，可以使电离平衡向电离方向移动。

（1）Kw取决于温度,不仅适用于纯水,还适用于其他溶液。25℃时， Kw =1×10-14， 100℃时，Kw =5.5×10-13

（2）在水溶液中,Kw中的c(OH-) 、 c（H+）指溶液中总的离子浓度. （3）溶液的酸碱性与c(OH-)、 c（H+）的相对大小有关

－－

（4）常温下,任何稀的水溶液中Kw= c(H+)×c(OH)===1×1014

－

（5）不论是在中性溶液还是在酸碱性溶液，水电离出的c(H+)＝c(OH)

＋－＋－

（6）根据Kw=c(H)×c(OH) 在特定温度下为定值,c(H) 和c(OH) 可以互求.