Watching the online open courses of some famous European and American universities _______a new fashion among white collars in China over the past few months.
The book was written in 1946, __________the education system has witnessed great changes.
For many cities in the world, there is no room to spread out further, ________New York is an example.
Gun control is a subject _________Americans have argued for a long time.
She’ll never forget her stay there _________-she found her son who had gone missing two years before.
—What do you think of teaching, Bob? —I find it fun and challenging. It is a job __________you are doing something serious but interesting.