题目内容：

We made a survey among 1,000 middle school students about their masks (口罩)for the coming school days. In general, every student will prepare 200 masks for it. The form below  shows that the number of each student’s medical masks is________as large as that of Kn95 respirators (Kn95口罩).

surgical (外科) masks (medical)	disposable（一次性）masks （medical）	Kn 95 respirators
100	50	?

 

 

A.twice B.three times C.four times