I have never seen modern machine. [ ]
A. so a
B. a such
C. such a
D. so
答案：C
下面的短文中，每一篇有10处语言错误，每句中最多有两个。错误涉及一个单词的增加，删除或修改。增加：在缺词处加一个漏字符号（∧），并在其下面写上该添加的单词。删除：把多余的单词用斜线（﹨）划掉。修改：在错误的词下划一横线，并在该单词下面写上修改后的单词。
注意：1. 每处错误及其修改均仅限一词 2. 只允许修改10处，多出者（从第11处起）不计分。
I saw the worst storm in years on last Friday. It came down suddenly but lasted for more than three hour. After lunch, I went into my room to have rest. The air was hot and everything that was quiet. Then strong wind start blowing into my room. Pieces of paper on my desk flew highly into the air and some blew out of the window. As I ran out catch them, big drops of rain began to fall. After a while I hear a big tree falling down and break the top of the back room.
主要适用于从全社会利益来看，必须限制使用的“公共劳务”的定价政策是( )。
A．平价政策
B．免费政策
C．低价政策
D．高价政策
