皮皮学，免费搜题
登录
搜题
【单选题】
“飘尘”是物质燃烧时产生的粒状漂浮物，颗粒很小（直径小于10 -7 m），不宜沉降（可漂浮数小时甚至数年），它与空气中的S0 2 接触时，S0 2 会转化为S0 3 ，使空气酸度增加，飘尘所起的作用与下列变化中硫酸的作用相同的是（ ）A.
浓硫酸与木炭共热
B.
胆矾中加浓硫酸
C.
乙酸乙酯与稀硫酸共热
D.
浓硫酸滴到蔗糖中制“黑面包”
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】Disfigurement of Businessman In the relationship of education to business we observe today a fine state of paradox. On the one hand, the emphasis which most business places upon a college degree is so...
A.
businessmen are both unmindful of history and sophisticated in it
B.
businessmen show both contempt and respect for noble activities
C.
there are both highly intellectual and uneducated businessmen
D.
there are both noticeable similarities and differences between businessmen and intellectuals
【单选题】下列关于肺炎链球菌转化实验的叙述正确的是
A.
加热杀死的S型细菌中，DNA全部失去活性。
B.
加热杀死的S型细菌能使小鼠的体细胞发生转化。
C.
加入用蛋白酶（或RNA酶、脂酶）处理的S型细菌的细胞提取物后，只有部分R型细菌转化成了S型细菌。
D.
在转化过程中加热杀死的S型细菌中的DNA没有进入R型活细菌。
【判断题】财务管理中的杠杆效应是由于特定费用（如固定成本或固定财务费用）的存在而导致的，当某一财务变量以较小幅度变动时，另一相关财务变量会以较大幅度变动。（ ）
A.
正确
B.
错误
【单选题】In the relationship of education to business we observe today a fine state of paradox. On the one hand, the emphasis which most business places upon a college degree is so great that one can almost vi...
A.
businessmen are both unmindful of history and sophisticated in it
B.
businessmen show both contempt and respect for noble activities
C.
there are both highly intellectual and uneducated businessmen
D.
there are both noticeable similarities and differences between businessmen and intellectuals
【单选题】In the relationship of education to business we observe today a fine state of paradox. On the one hand, the emphasis which most business places upon a college degree is so great that one can almost vi...
A.
businessmen are both unmindful of history and sophisticated in it
B.
businessmen show both contempt and respect for noble activities
C.
there are both highly intellectual and uneducated businessmen
D.
there are both noticeable similarities and differences between businessmen and intellectuals
【单选题】We observe today not a victory of party but a celebration of freedom .
A.
celebrate
B.
preserve
C.
orate
D.
help
【简答题】We observe today not a victory of party but a celebration of , symbolizing an end as well as a beginning, signifying renewal as well as change for I have sworn before you and Almighty God the s...
【简答题】如果教学数据库中的关系如下:教师关系T(T#,TNAME,TITLE),课程关系C(C#,CNAME,T#),学生关系S(S#,SNAME,AGE,),选课关系SC(S#,C#,SCORE),用断言写出每门课程最多50名男生选修的完整性约束。
相关题目：