生产性粉尘对人体的危害程度与其理化性质有关。其中与矽肺病的发生最密切的化学特性是()。
A.爆炸性
B.分散度
C.游离二氧化硅含量
D.溶解度
参考答案:C
-Do you know how many counties_______ during his journey to Europe last month?
-Quite a few. He was warmly welcomed by the countries' leaders.
A.did President Xi visit
B.President Xi visited
C.has President Xi visited
D.President Xi has visited
当支路板收到的下行信号为全“1”信号时,2M端口会出现E1-AIS告警,但由于TU-AIS告警的存在,此告警将被屏蔽。()