（）对粉尘爆炸压力上升速率的影响比粉尘爆炸压力大得多。
A．粉尘粒度
B．初始压力
C．粉尘爆炸容器
D．湍流速
参考答案：A
下列不属于原发性皮损的是
A．斑疹
B．丘疹
C．疱疹
D．脓疱
E．鳞屑
The little boy was late again. Her teacher got annoyed _________ him . [ ]
A. at
B. with
C. to
D. from
