Question

Tom used to be a lazy boy,he () while his classmates were studying. A.were sleeping B.was sleeping

C.sleeping D.sleeps

Answer 1

Tom used to be a lazy boy,he () while his classmates were studying.
A.were sleeping B.was sleeping
选B。
因为Tom 是【单数旦启名词】
如果我帮到旅汪了你，请采纳，谢谢！拆迟仔

Answer 2

used to be表示过去常常 过去是.....

Tom是第三肆樱人称 be动词用is /was.
后面while his classmates were studying.根据动词were，所以前面有个时裂雹丛肆侍态一致。
所以选B