主要靠增加组织中cAMP而发挥作用的药物是
A．β-受体激动剂B．白三烯受体拮抗剂C．抗过敏药D．肾上腺皮质激素E．抗胆碱药
参考答案：A
The teacher didn't begin the class _____ all the students _____. [ ]
A. until, stopped to talk
B. before, stopped to talk
C. when, stopped talking
D. until, stopped talking
（）属于镂空雕。
A.南瓜蛊
B.山茶花
C.西瓜蛊
D.西瓜灯
