Unit 3　The world online
(主题语境:人与社会——科学与技术)

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高频单词
重点短语
难点句型
1.command n.命令;控制;掌握　vt.命令;指挥;控制[经典例句] I have such a good command of English that I am elected as assistant to my English teacher.我英语很好以至于被推选为英语老师助手。(1)have a good command of...精通……;掌握……in command of...指挥……(带有主动意味)in/under the command of由……指挥(带有被动意味)at one’s command听某人支配(2)command sb.to do sth.命令某人做某事(3)command that...命令……,从句用虚拟语气,即谓语动词为(should)do形式。command后面宾语从句、表语从句或同位语从句惯用虚拟语气,谓语形式是“should+动词原形”,should可省略。与command使用方法一样单词还有demand, ...