参与Ⅰ型超敏反应的物质有()
A.前列腺素
B.白三烯
C.组胺
D.激肽原酶
E.以上均正确
参考答案:E
— at this season of the year in the north?
—It's much hotter than last year. The high temperature has lasted for days.
A. How are things going
B. How are you getting on
C. What's the weather like
D. What do you do
推煤机作业,应当遵守下列规定:()。
A、雨季施工,作业完毕,停放在较高的坚实平坦地面上,并使推刀着地。
B、夜间作业,机上及工作地点的照明充足。
C、行驶中,驾驶员不得与地面人员传递物件
D、在缓坡上不得横向行驶,纵向行驶不得拐死弯。