This is the first time astronomers ____the whole process of

来源：学生作业帮编辑：灵鹊做题网作业帮分类：英语作业时间：2024/05/24 03:59:06

This is the first time astronomers ____the whole process of a black hole ___a star, from its first
to nearly final bites.
A see eat B have seen eating C saw eaten D had seen eat
这个句式是不是用完成时呢?

是用现在完成时
It/This is the first/second/……/last time that +现在完成时
It/This was the first/second/……/last time that +过去完成时

This is the first time astronomers ____the whole process of this is the first parent meeting for you.the time of it is f This is the first time I ______(wear)this kind of dress. is this the first time that jack ——this kind of food? This is the first time that Apple has changed the size of th This is the first time for me to love one from the bottom of 12.The first astronomers were _______________. It is the first time that I have enjoyed this kind of moon c this is the first time this was the first time 怎么用,有什么区别? This has been the first time与this is the first time有什么区别 This,I think,____the first time that we____traveling togethe this is the first time i came to china和this is the first tim