在载波侦听与总线访问方法上，CSMA/CD类似( )CSMA协议。A．1-坚持式

二战后，世界政治格局发生变化的主要原因是 [ ]

A．国际性会议的召开

B．世界性组织的成立

C．反法西斯战争的胜利

D．政治力量对比的变化

短文改错

文中共有10处语言错误，每句中最多有两处。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（∧），并在其下面写出该加的词。

删除：把多余的词作斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1．每处错误及其修改均仅限一词；

2．只允许修改10处，多者（从第11处起）不计分。

Helen was a twenty-years-old girl. She has never had a job before. Now she wanted to get a work. So she went to meet Mr Black, the manager of hotel. Mr Black told her it was getting very busy in the hotel at the evening. He ask her if she was interesting in a part-time job. The girl said that she did. Then Mr Black said she had to work very fast and that she must be there at six every afternoon and work from six to ten, from Monday to Friday. He offered her with 4.5 dollars an hour. Hellen pleased with the offer and decided to start work the next day.

石油农业与无废弃物农业相比，其主要优点是（）

A.物质可以循环利用，对环境几乎没有破坏性

B.使用植物易于吸收的化肥作肥料，在促进植物快速生长的同时也有助于周围环境的净化

C.以煤和石油等原料为动力，极大地提高了生产效率

D.是一种低投入高产出的农业生产方式