问题 解答题
某汽车生产企业,上年度生产汽车的投入成本为8万元/辆,出厂价为10万元/辆,年销售量为12万辆.本年度为节能减排,对产品进行升级换代.若每辆车投入成本增加的比例为x(0<x≤1
2
)
,则出厂价相应提高的比例为0.75x,同时预计年销售量增加的比例为0.5x.
(1)写出本年度预计的年利润y与投入成本增加的比例x的关系式;
(2)当投入成本增加的比例x为何值时,本年度比上年度利润增加最多?最多为多少?
答案
选择题
改错题

短文改错(共10小题;每小题1分,满分10分)

此题要求改正所给短文中的错误。对标有题号的每一行作出判断:如无错误,在该行右边横线上画一个勾(√);如有错误(每行只有一个错误),则按下列情况改正:

此行多一个词:把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。

此行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线上写出该加的词。

此行错一个词:在错的词下面画一横线,在该行右边横线上写出改正后的词。

Last summer I go to America and studied at a language              56.          

school. I had many wonderful experience, but I also                57.          

had a sad one. One day, the school held party, where                 58.          

I invited to talk about Tianjin. After that they asked me a lot of        59.          

Things about China. But I couldn’t explain them with English         60.          

Clearly. I felt sadly. I learnt a lesson from this experience. I           61.          

have already studied English for eight years, I can’t use it            62.          

very good. I must work hard to improve my spoken English          63.          

so that I will not be able to communicate freely with foreigners.       64.          

I hope I can be a bridge between China and others countries          65.          

in the future.