Though Mandela﹙曼德拉﹚____27 years in prison﹙监狱﹚, he thought it meaningful.
My sister told me _________ to the movie theatre.
I did my homework ______________;
It’s the best way English.
The room is _____with lots of people.
—How about the pollution in the countryside? —Luckily, it's not as serious as _______ in the big cities.