问题
单项选择题
生产性粉尘的理化性质不包括( )。
A．粉尘分散度
B．浓度
C．比重
D．溶解度
答案
参考答案：B
解析： 粉尘对人体的危害程度与其理化性质有关，与其生物学作用及防尘措施等也有密切关系。在卫生学上，常用的粉尘理化性质包括粉尘的化学成分、分散度、溶解度、密度、形状、硬度、荷电性和爆炸性等。
搜题请搜索小程序“爱下问搜题”
生产性粉尘的理化性质不包括( )。
A．粉尘分散度
B．浓度
C．比重
D．溶解度
参考答案：B
解析： 粉尘对人体的危害程度与其理化性质有关，与其生物学作用及防尘措施等也有密切关系。在卫生学上，常用的粉尘理化性质包括粉尘的化学成分、分散度、溶解度、密度、形状、硬度、荷电性和爆炸性等。
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| I want you to know about our neighborhood, Tangley Heights, a slum(贫民窟). I didn't go there much after I met Maxine and her disabled son Ronald and their friend, Miss Annie.In 1981 I was 12 years old. I __1__that once you are 12, you are too big for lots of things you used to __2__before, but you are too young for a job.So a whole group of us children were __3__with nothing to do, only standing at the corner to __4__if Maxine would come with popeyed(突眼的)Ronald.Somebody found that Ronald went to a school for mentally __5__kids and that every afternoon a special bus brought him home and that his mother was always there to __6__him off the bus. My mama could always make you feel special.She could see what my teachers could not, but that was a __7__between us.When my mama died, the secret died, too.It was Maxine who __8__me to her neighbor, Miss Annie, when I needed __9__with English.She told me to bring my book to her house every day after school.After a few weeks, Miss Annie said, "Vernon, I have never __10__you for money, but I would like you to help Maxine __11__up her yard." I cleaned up the yard, and then put the __12__in a bag that Ronald held.Ronald stood there __13__ the bag as if it were the most important job on earth.When you first saw Ronald, he looked like a (n) __14__animal, but what I understood was that Ronald's problem was __15__.Being scared made him look strange. | ||||
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