She’s already an hour late, What _____to her? A can have happened B may happen C should have happened D may have happened
--Reading is the best way to pass time on the train.-- , I never go traveling without a book.
When it ________ air pollution, Beijing faces the three “C”s, cars, coals and construction, which lead to Beijing’s thick air pollution.
It remains ______ whether Jim will be fit enough to play in the finals.
English is ________ hard for me and Physics is ________ harder.
Hi, Doctor Wang, my chest _______ when I make a deep breath.