The city plan to cut pollution by thirty percent.
- JohnnyLv 76 years agoFavorite Answer
版大您好 我查詢了一些文法書 整理出來 供您參考
The letter was evidently written by a foreigner.
She was blinded by the bright lights.
His skull had been crushed with a heavy object.
She made a bit of money by selling her paintings.
May I pay by credit card?
She’s arriving in London by air this afternoon.
There was a low table by her chair.
The bus flew by me before I could stop it.
By five thirty she was feeling pretty hungry.
5.2by day指「白天的時候」，by night指「晚上的時候」：
Owls sleep by day and hunt by night.
He was quite a shy person by nature.
7.by trade、by professional指「以…為職業」
Her next boyfriend was Jack, who was a psychologist by profession.
Employers must by law employ workers from minority groups.
Divide twenty-seven by three.
Four multiplied by three is twelve.
The bedroom was about ten meters by six (= 10m long and 6m wide).
The situation was worsening by the hour (=very quickly).
Prices have risen by an average of 4% this year.
Interest rates are to be cut by 1%.
Her sister was taller by at least two inches.
I only missed my train by a couple of minutes.
little by little（一點一點地）、day by day（一天一天地）這種說法用來表示持續漸進的過程：
Add the milk bit by bit.
One by one the musicians left the stage.
- 6 years ago
- DaSaGwaLv 76 years ago
By the way, "plan" needs to be "plans".
Using "by" is for showing how much something has changed.
2014-04-08 11:52:40 補充：
Let me give you some more examples:
House price will rise by 15% this year.
He missed the train by a couple of minutes yesterday.
Usain Bolt broke the world record by 3 seconds.
"by" in your sentence, you can translate it as "按" or "以......計算".