When the man saw the car accident on the hightway ,he stopped ( ) offer help .

问题描述:

When the man saw the car accident on the hightway ,he stopped ( ) offer help .
when the street light go on ( ) they make a beautiful picture ,so different from the daytime

to(不定式结构作目的状语)
When the street lights go on (at night) they make a beautiful picture,so different from the daytime.(提醒:与后面的daytime相对.)