干槽症症状出现的时间是（）
A.拔牙当天
B.拔牙术后3天
C.拔牙术后7天
D.拔牙术后14天
E.拔牙术后30天
参考答案：B
A和B都是非0自然数，且7A=B，那么A和B最小公倍数是______．
—Morning,class! Today is Monday.What's the date today?
—_________[ ]
A. It's fine
B. It's Friday
C. It's June 14
D. It's summer
