一本故事书有192页，小明每天看32页，小强每天看48页，小明比小强迟几天看完？

Their mother ________ dinner at the kitchen when a quarrel ________ among the children.[ ]

A. was preparing; was broken out

B. prepared; was broken out

C. was preparing; broke out

D. prepared; broke out

下列疾病有家族史的是（）

A.假性斑秃

B.斑秃

C.男性型秃发

D.普秃

E.以上都不是

简述练习在物理教学中的作用。

要约可以撤销。撤销要约的通知应当在（）到达受要约人。

A.受要约人发出承诺通知之前

B.要约人收到要约之前

C.与要约同时

D.要约到达受要约人后