速发型超敏反应中引起皮肤奇痒的物质是（）
A.白三烯
B.前列腺素
C.组织胺
D.激肽
E.ECF-A
参考答案：C
—I'm stressed out. I have so much work to do every day.
—You 'd better rest very often. And it's good for you to take some_____ I think.[ ]
A. health
B. exercise
C. lesson
D. work
催化剂是化学反应中的（）
A、生成物
B、填充物
C、媒介物
D、以上均错误
