It is the country _____I studied English _____ I am going to visit next week [ ]

Mary has recently got engaged ________ a foreign teacher, who has been engaged ________ education research for years

The black baby boy is at the stagehe can only say a few simple words but not yet full sentences．

I ______ go to bed until I ______ finished my work

We didn’t see Smith at the meeting-He______about the lecture