Built mainly on natural resources , the prosperity of the city was _______ and its economy almost collapsed when coal prices began to fall in 2012.
Every minute must be made full use of________spoken English.
As you can see,the number of cars on our roads________rising these days.
Ten minutes later,a bus________and everybody got on it.
I have some trouble________physics.I would be grateful________you if you could give me some advice on it.
—Have you ever been to Shanghai Expo Garden? —No.It is the first time that I________to China.