生产性粉尘按性质可分为三类,它们分别是( )。A.有机粉尘、无机粉尘和放射性粉尘B. 发布时间:2017-06-18 06:08 │ 来源:www.tikuol.com 题型:单项选择题 问题: 生产性粉尘按性质可分为三类,它们分别是( )。A.有机粉尘、无机粉尘和放射性粉尘B.有机粉尘、无机粉尘和混合粉尘C.矿物粉尘、有机粉尘和无机粉尘D.金属粉尘、非金属粉尘和有机粉尘
题型:单项选择题 —I hear there will be a concert of Sun Yanzi and I've been waiting for it. _______ will it start? —Well, take it easy. In two days.A. How soon B. How long C. How often D. How far 查看答案