____ was known to all, John had broken his promise ___ he would stay with us for some time .
---What are you busy doing these days?---____ the college entrance examination.
To save class time, our teacher has ____ students do half of the exercises in class and complete____ for homework.
I hope you don’t mind me asking, ____ where did you buy these books?
On March14, 2013, Xi Jinping was elected____ president of ____ People’s Republic of China.
— Tom, I made your computer system break down. I will pay someone to repair it.— Oh. ______. I can solve it by myself.