“不时”造句

他们不时地听到大卡车的轰鸣声。
Now and then they heard the roar of a heavy truck.

人群里不时发出几声抱怨和欢呼。
Scattered groans and whoops broke out in the crowd.

要抬起头，不时看看四周。
Keep your head up, and look around you from time to time.

• #不时