小玲早上7:00到校,11:00放学,她上午在校______小时.
11-7=4(小时);
答:她上午在校4小时.
故答案为:4.
—Listen ! Helen is singing in the next room.
—It _______ be Helen. She has gone to Beijing.
A.can’t
B.mustn’t
C.may
D.should
分珠散功效与作用