具有升华性的生物碱是（）
A.喜树碱
B.蛇根碱
C.咖啡因
D.长春碱
E.毒芹碱
参考答案：C
根据情景， 完成对话。
A: What's your favorite 1_____?
B: Dolphins.
A: Why do you like 2_____?
B: 3_____ they are very friendly, what about you?
A: I like 4_____. Do you know 5_____ they are 6_____ ?
B: Sichuan, China, I 7_____.
A: You're 8_____.
B: Let's 9_____ to the zoo tomorrow.
A: OK, I want 10_____ them, too.
β受体激动剂（）
A.沙丁胺醇
B.异丙托溴铵
C.氨茶碱
D.孟鲁司特
E.二丙酸倍氯米松
