掺入引气剂能使混凝土()。
A.改善和易性
B.提高抗渗性
C.提高抗冻性
D.降低强度
E.提高强度
参考答案:A, B, C, D
从Ⅱ栏中选出与Ⅰ栏匹配的选项。
Ⅰ Ⅱ
小题1:Where is Jane? A. Because I can’t catch the early bus.
小题2:Why are you late for school today? B. She has gone to Cuba.
小题3:What’s the matter with you? C. Of course. I’d love to.
小题4:Has Ann jumped rope? D. No. She hasn’t.
小题5:Would you like to be a greener person.? E. It’s difficult for me to breathe.
心迷走神经节后神经元末梢释放的递质是
A.多巴胺B.血管紧张素C.乙酰胆碱D.5-羟色胺E.组胺