Correct

敲门砖

/ qiāoménzhuān /
Strokes

Definition

lit. a brick as a door knocker (idiom); fig. a temporary expedient/to use sb as a stepping stone to fortune

Example

As a Noun

brick picked up to knock on the door and thrown away when it has served its purpose―stepping-stone to success

1
Yǒurén
有人
shàngxué
上学
dàngchéng
当成
qiāoménzhuān
敲门砖
  
,
dàn
一旦
gōngmíng
功名
dàoshǒu
到手
  
,
shū
书籍
jiù
bèi
shùzhīgāo
束之高阁
le
  

Some people take attending school only as a stepping-stone to status; once they succeed, all the books will be shelved.

Related

敲门砖