Knowing how long the text would last,the students who finished( )back and waited .
问题描述：
Knowing how long the text would last,the students who finished( )back and waited .
Knowing how long the text would last,the students who finished( )back and waited until the end of the exam.
A settle Bsetted C settling D to settle
答
B.settled
这里需要谓语动词,和waited并列的谓语动词,所以是一般过去时settled
who finished 是定语从句,修饰students
去掉定语从句,句子结构就立现：
the students settled back and waited until...（学生又坐回原位,并等待考试结束）