Correct

登时

/ dēngshí / 
Strokes

Definition

immediately/at once

Example

As an Adverb

immediately; at once; then and there

1
Zhùshè
注射
hòu
后
  
,
tā
他
dēngshí
登时
huīfù
恢复
le
了
zhījué
知觉
  
。

He came to himself at once after the injection.