Today there are about seven million Americans in the colleges and universities. Young persons under twenty-five make up nearly half of the American population. Many of these will soon be in charge of the nation. Naturally, their ideas are important to everyone in the country, and it is necessary for older people to understand what they think and feel.
College students today have strong opinions about right and wrong. They are deeply interested in making a better life for all people, especially for those who have not been given a fair chance before now. They see much that is wrong in the lives of their parents. It is hard for them to see what is right and good in the older ways. As a result, there is often trouble in American families.
Which of the following statements is true?
A.People haven't written much about American youth.
B.Writers have wasted a great deal of their effort(努力)to write about American youth.
C.Much has been written about American youth.
D.Young people's ideas are not important enough to the United States.
第4题
重介分选机中悬浮液上层和下层的密度差越大则()
A.悬浮液稳定性越好,分选效果越好
B.悬浮液稳定性越差,分选效果越差
C.悬浮液稳定性越差,分选效果越好
D.以上都不对
第7题
A.粗煤泥分选可以用TBS或浅槽
B.粗煤泥分选可以用煤泥旋流器或摇床
C.煤泥重介的分选密度可以控制
D.TBS的分选密度可以是1.4-1.9
E.粗煤泥分选的入料粒度范围越宽,效果越好
为了保护您的账号安全,请在“上学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!