Mr Li, who is in charge __ our class, will have a talk __you

How I wish that you could attend the party, even though you _____busy.

It is already well understood causes the global warming

Someseeminglyharmlessblogsmightbecomeharmfulwhen_____ontheInternetbymillionsofpeople [ ]

The book has helped me greatly in my daily communication, especially at work ________ a good impression is a must.