在生产条件下,金属汞主要以( )形式经呼吸道进入人体
A. 粉尘
B. 烟
C. 蒸气
D. 雾
E. 粉尘和烟
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下列属于刺激性气体的是( )
A. CO2
B. 一氧化碳
C. 二氧化氮
D. 甲烷
E. 以上都是
长期接触高浓度的苯可引起
A. 白血病
B. 肝血管肉瘤
C. 肺癌
D. 膀胱癌
E. 皮肤癌
Civil servants who are concerned with administration are forbidden ________.
A. to be voters at elections
B. to be candidates for parliament
C. to continue their work when government changes
D. to compete with others for a higher rank
In Britain, government cannot spend any money without the permission of________.
A. the Queen
B. the Prime Minister
C. the House of Lords
D. the House of Commons
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