go through the floor

US /ɡoʊ θruː ðə flɔr/
UK /ɡoʊ θruː ðə flɔr/
"go through the floor" picture
1.

一落千丈, 跌入谷底

to fall to a very low level; to decrease very quickly

:
Sales of the product went through the floor after the scandal.
醜聞發生後,該產品的銷量一落千丈
House prices in the area have gone through the floor.
該地區的房價已經跌入谷底