28.The Changbaishan Mountains have a huge variety of scenery, some of the best of__________can only be reached on foot.
---- Mary looks sad. What _________ her ?-----She failed in the maths exam.A. happened to B. happened C. was happened D were happened
This is the first time that I ___________ at the meeting.
I can’t stand _________ with Jane in the same office. She just refuses ______ talking while she works.
My advisor encouraged _______ a summer course to improve my writing skills.
It is difficult to imagine his _____ the decision without any consideration.