The police have been the area for quite a long time.-I’ve also noticed thatWhat have they been ?[ ]

It is the first time that I _______ thiskind of tasty moon cake.

His uncle went abroad in 2010, and __________ since

Do you like _____here—Oh, yes, the air, the weather and theway of life Everything is so nice

I found the lecture hard to follow because it _______ when I arrived