Module 3 The natural world

by的用法
①在……旁邊, 從……旁邊(經過)
i put the vase back on the table by the window.
②通過, 經由, 取道
he rose quickly and went out by another door.
③在(某時)前, 到……時為止
by next friday i will have finished the work.
i will be back by three.
④表示動作的執行者
have you read that novel by shirley?
⑤表示手段或方式, 可譯為 “通過……, 用……, 以……, 按照……”
it is nine o’clock by my watch.
⑥表示工具
i came here by bus.
she called him up by telephone to thank him.
⑦和seize, take, hold等動詞連用, 說明接觸身體的哪一部分
he took the child by the hand.
⑧(指數量)按……計算
these workers are paid by the week.
i rent the house by the year.
⑨表示數量增減或差別的程度
he is older by five years than john.
⑩表示尺寸, 距離等, 相當于 “乘以”
i want a piece of paper 3 inches by 5 inches.
this room is forty feet by twenty.
⑾詞組和固定搭配:
by accident偶然地;
by chance偶然地, 碰巧;
by means of借助于, 靠;
by mistake出于誤會, 弄錯了;
by oneself單獨地, 獨立地;
by the way順便說;
by turns輪流;
learn by heart記熟;
one by one一個接一個地;
little by little一點點地;
side by side并肩地, 并排地
(四) 連詞if的用法
1. (表示條件)如果，主句用將來時，if從句用現在時表示將來
he will come if you invite him.
如果你請他,他會來的。
2. (表示虛擬)假如,要是
1）時態：可以表示過去，現在和將來的情況。它的基本特點是時態退后。
句型：條件從句 主句
一般過去時 should( would) +動詞原形
if they were here, they would help you.
2）表示與過去事實相反的假設。
句型：條件從句 主句
過去完成時 should(would) have+ 過去分詞
if she had worked harder, she would have succeeded.
if he had come yesterday, i should / would have told him about it.
3）表示對將來的假想
句型： 條件從句 主句
一般過去時 should+ 動詞原形
were+ 不定式 would + 動詞原形
should+ 動詞原形
if you succeeded, everything would be all right.
if you should succeed, everything would be all right.
if you were to succeed, everything would be all right.
3. 是否 = whether 連接賓語從句
i wonder if she is ill.
不知她是否病了。
(五) 情態動詞can的用法
can表示說話人的主觀看法或語氣｡
它沒有人稱和數的變化,也不能單獨在句子中作謂語,但它可以與其后的不帶 to 的動詞不定式一起構成動詞性復合謂語｡其基本用法如下:
1. 表示能力,常被譯成“能”､“會”｡例如:
her sister can speak english. 她姐姐會講英語｡
i can sing english songs. 我會唱英語歌曲｡
2. 表示請求或許可,即常被用來請求對方的許可,或表示說話人自己的許可｡例如:
can i help you? 我能幫你忙嗎?
can you go to the picnic with us tomorrow? 明天你能和我們一起去野餐嗎?
you can sit here. 你可以坐在這兒｡
3. can 的否定式和疑問式
① can 的否定形式是 cannot 或 can not,其縮略形式是 can’t｡例如: