present perfect

常见例句

When you ask about something that started in the past but continues to the present time, you use the Present Perfect tense, e.g.
当你谈论从过去开始一直持续到现在的某件事时，用现在完成法时态。
edu.sina.com.cn
When you ask about something that started in the past but continues to the present time, you use the Present Perfect tense, e.g.: I’ve been there for 5 years / I’ve been there for 5 years.
当你谈论在过去开始但是一直持续到现在的某事时，用现在完成时态，例如：I’ve been there for 5 years/我在那里已经5年了。
edu.sina.com.cn
If we say when a past event happened (for example, by using time-adverbs), we do not usually use the present perfect.
说过去发生的事件（例如：用过去时间状语），我们通常不用现在完成时。
blog.sina.com.cn

This pullback could present the perfect buying opportunity.
FORBES: Buy BBBY While Shares Are Below Recent Highs
But just like the guy who bought the older Volkswagen off my dad, I rarely believe those who present everything as perfect without any dents or challenges.
FORBES: How To Sell Without Being A Salesperson
Pick-n-mix, and you have the perfect millennium present.
ECONOMIST: Shakespeare on tape: Audio-Bard The