精品文档描述时间1. It is (has been)+一段时间 +since sb. did sth.2. It/this/that is the first(second) time that sb. have done sth.3. It is +形容词的最高级 +that sb. have done sth.4. Hardly/scarcely had sb. done sth. when sb. did sth.5. No sooner had sb. done sth. than sb. did sth.6. It was the first/ last time that sb. had done sth.7. be doing sth.8. be about to do sth.when sb. did sth.9. have done sth.过去的时间， （过去完成时）10. By the time of +现在的时间，+主句（现在完成时） 将来的时间， （将来完成时）11. It w
