scratch where someone itches

(1) scratch where someone itches即appropriate or relevant to someone's needs，指「適合他人需要」或「迎合人意」，例如：

The book really scratches where I itch-it's very helpful.

此書確實符合我的需要，對我大有幫助。

茲介紹幾種含scratch的習語：

(2) I've been scratching around for a job for over a month.

我到處找工作，已超過一個月。

（Modern American Colloquialisms）

(3) They scratched along that year with very little money.

那一年，他們勉強度日，十分拮据。
(4) I had to scratch my head to remember his name.

我要苦思才能記起他的名字。
(5) Scratch his name out, please.
請把他的名字劃掉。
(6) I'll manage to scratch some money up somehow.

我會設法湊起一些錢來。

（陸谷孫《英漢大詞典》）