while与when的用法
①when的含义是at or during the time that，既可用于指一点时间(从句的谓语动词需用终止性动词)，也可用于指一段时间(从句的谓语动词用延续性动词)，从句与主句里面的谓语动词所表示的动作或状态能同时发生，或一先一后发生。
He wants to help people . 他想在人们生病的时候帮助他们。
， the ship had already set off. 他到达上海时，轮船已经开走了。
②while的含义是during the time that，只能用于指一段时间(从句的谓语动词必须是延续性的)，从句与主句里面的谓语动词所表示的动作只能同时发生，不能一先一后发生。
， my mother was washing clothes. 我读书时，妈妈在洗衣服。
③这两个词还可以用作并列连词。when表示"在那时"或"这时"，相当于and just at that time的意思，用来连接两个并列分句，有时when分句之前有逗号把前后两个分句分开。
I stayed till sunset, . 我一直呆到太阳下山，这时天开始下雨了。
④while意为"而，却"，表示对照关系。
Some like collecting stamps, . 有些人喜欢集邮，而有些人却喜欢种花。
点拨： hear, hear from, hear of与hear that……的用法：
1)hear sb./sth."听到某人或某物的声音"。
I can't at all. 我根本就听不到你的声音。
Haven't you heard anything? 难道你没有听到什么声音？
2)hear sb. do sth."听到某人做某事"。
I often in the morning. 我经常在早晨听到李平读英语。
3)hear sb. doing sth."听到某人正在做某事"。
I in the next room.我听见他正在隔壁房间里唱歌。
注意：hear sb. do sth.指听到整个行动或整个事件；而hear sb. doing sth.是指听到了行动的一部分，有正在发生的意思。试比较：
I the stairs.我听到这个男孩走下楼去。
I the stairs.我听到这个男孩下楼的声音。
How often do you your father? 你每隔多久收到你父亲的信？
Have you still not him? 你还没有收到他的信吗？
I haven't since he telephoned.
自从他打电话以来，我一直没有他的消息。
注意：hear from的宾语是表示人的名词或代词，而不是表示信件的名词。
例如：我们好几个星期未收到他的信了。
误：We haven't heard from his letter for weeks.
正：We haven't heard from him for weeks.
正：We haven't got a letter from him for weeks.
I've never that before.我以前从未听说过那件事。
She disappeared and was never heard of again.
她不知去向了，再未听到她的消息。
One day, in a town not far away. 一天，史密斯一家听说不远的镇里有一位好医生。
I hear that one of the pandas has a baby. 我听说其中一只熊猫生了个熊猫宝宝。
意为"由……(原料)制成"，后面一般接物质名词。接from则表示某物品制成后，已看不出原材料是什么，原材料在制作过程中已起了化学变化；接of表示某物品制成后，仍可看得出原材料，其原料在制作过程中仅起了物理变化。
Nylon air, coal and water.尼龙是由空气，煤和水加工制成的。
The shoes cloth.这鞋子是用布做的。
知识拓展
①be made up of表示某物或某组织由一种种成分或一个个成员组成。
The world matter.世界是由物质构成的。
②be made into意为"把……做成……"，主语在意义上为原材料，介词宾语在意义上为制成品。
Bamboo paper.竹子也可以用来造纸。
③be made in意思是"在……(地点)制造"，介词in后接产地。
This kind of computer the USA.这种电脑是美国制造的。
④be made by意思是"由……制造"，介词by后跟动作的执行者。
This model ship Uncle Wang. 这个轮船模型是由王叔叔制作的。
Mr Brown was a rich shopkeeper. He 1 a lot of money to his son Jim when he was dying. The young man often 2 his friends to dinner and several years later he spent all the money on the 3 food. Now he got into trouble and nobody came to see him. It made him 4 and he went to ask a clever old man for advice.
"My money has 5 and my friends have gone," said the young man. "What will happen to me now?"
"Don't 6, young man," answered the old man. "Everything will soon be all right. 7 and you will soon feel much happier."
8 this, the young man was very glad. He asked, "Am I going to be 9 again then?"
"No," said the old man. "I 10 you will soon get used to being poor and to having no friends."
My biggest problem
My biggest problem is that I am too busy. When I was young, I used to have much time, but these days I get up early and in school all day. I go right home and eat dinner. I started high school, I used to spend a lot of time games with my friends, but I just don't have the time anymore. In the evening, I used to watch TV or with my grandmother, but now I to study. I love , and my father used to take me to the concerts. These days, I hardly ever have time for . I do homework and go to bed. I really the old days.
