HSK 6
Correct

以至

/ yǐzhì /
Strokes

Definition

down to/up to/to such an extent as to .../also written 以至于[yǐ zhì yú]

Example

As a Conjunction

down to; up to

1
Xúnhuánwǎng
循环往复
  
,
zhì
以至
qíong
无穷

repeat itself in endless cycles into infinity

As a Conjunction

to such an extent that...; so...that...

2
men
他们
tài
ruò
虚弱
le
  
,
zhì
以至
yào
需要
shū
特殊
zhìliáo
治疗
  

They were emaciated to such an extent that they needed special treatment.