4) 情态动词没有非谓语形式,即没有不定式,分词,等形式。 比较can 和be able to 1)can could 表示能力;可能(过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。They will be able to tell you the news soon.他很快就能告诉你消息了。 2)只用...
When you have finished the report, I will have waited for about 3 hours. 等你完成这份报告的时候,我就已经等了将近3个小时了。 2. 现在进行时(am/is/are doing) ①表示此时此刻正在发生的事情。 例:He is listning to the music now.
1、I'm feeling sick. I ___ so much chocolate. A. needn't have eaten B. couldn't have eaten C. mustn't have eaten D. shouldn't have eaten 2、They have done things they ought ___ A. not to do B. not to be done C. not to have done D. not having done 3...
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