98%浓硝酸具有（）性。
A.腐蚀
B.剧毒
C.易燃
参考答案：A
Professional player means that he should play _____.[ ]
A. part time
B. fell time
C. full time
D. fill time
从建筑主体通向直升机停机坪出口的数量不少于2个，且每个出口的宽度不宜小于（）。
A．0．90m
B．1．00m
C．1．10m
D．1．20m
