圈形卡环适用于
A.孤立切牙B.孤立双尖牙C.孤立尖牙D.孤立磨牙E.牙弓末端孤立磨牙
参考答案:E
经济波动为什么会有上限和下限?
—John and I will celebrate our fortieth wedding anniversary next month. —Oh, ()!
A.cheer up
B.well done
C.go ahead
D.congratulations