American and British English speakers use the present perfect verb tense in similar ways.

英英语和美英语在现在完用上是比较相似。

Now we have a filtration type of lab that you can do literally at home.

而现在，我们有了一种在家里完过滤检测方法。

Please make a sentence using the present perfect tense.

请现在完时态造句。

So is the world made for introverts or extroverts?

今天 usage tip 是介绍 it 加 has been 加过去词 加 that 句型 它用於间接引述 许主词 it 作为开头 搭配现在完被动语态 表达一直来都有 that 子句所述主张 常用於本句型动词 大多具有声称或是揭露含义 除了 argue 外呢 此句型也用 claimreveal， report 等字词用被动语态淡化消息来源并将重点放在所主张内容上来看例句It has been revealed that several celebrities were involved in the scandal据透露有多位名人卷入这起丑闻？

When I have a class, I'll usually do a few lessons on past perfect before moving on.

当我上课时候，我通常会先上几节关于过去完课，然后再继续学习。

So, if you feel that you need some more practice, by all means, watch that individual class on the past simple, on the past perfect, okay?

所，如果你觉得你需要更多练习， 一定要看那个简单过去， 过去完个人课程，好吗？

Well, first of all you probably realize these are all present perfect progressive sentences, and they have a lot of things in common.

好吧， 首先你能意识到这些都是现在完进行句子，它们有很多共同点。

So we should be able to get to a South Korea-type prioritized testing thing within a few weeks.

所我们应该能够在几周内完韩国优先测试。