关税政策的保护作用只是对于最终产品而言。

短文改错（共10小题；每小题1.5分，满分15分 ）

此题要求对一段文章改错。先对每一行做出判断是对还是错。如果是对的，在该行右边横线上画一个勾（√）；如果有错误（每行不会多于一个错误 ），则按情况改错如下：

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，在错的词下划一横线，在该行右边横线上写出改正后的词。

注意：原行没有错的不要改。

Most Americans would find it hard to think that what life   小题1:____________

would look like without a car. But, some have realized    小题2: _______ ____

the serious question of the pollution caused by the car.  小题3: ____ ________

The polluted air becomes harmful and dangerous to health.  小题4: ___ ________

One way to getting rid of the polluted air is to build a   小题5:____________

car that doesn’t cause pollution. That is how several of the  小题6: ____  ______

large car factories have been tried to do. But to build       小题7: _________   

a clean car is more easier said than done. Progress in this   小题8:_________   

field has been slow.

Another way is to take place of the car engine by a     小题9: ___________ 

steam one. Inventors are now working on steam cars as well as

electric cars. Many makers believe that it will spend         小题10: __________  

years to develop a practical model that pleased people.

如果某投资组合由以下两种资产构成，那么该投资组合的预期收益率为( )。

A．7%
B．10%
C．13%
D．16%

下列叙述中正确的是______。

A．线性表是线性结构

B．栈与队列是非线性结构

C．线性链表是非线性结构

D．二叉树是线性结构

整理随车工具，锁上车门及其它应锁好的各部（如燃油箱盖、发动机侧板等）。