10. By the middle of the 21st century , the vast majority of the world’s population ________ in cities rather than in the country.
— Why not take my car to the museum instead of walking? — No, thanks. ________.
The thing that ________ is not whether you fail or not, but whether you try or not.
— Why weren't you at school yesterday morning, Li Lei? — ________, sir.
.If the launch in 2005 is successful, China will be the third country ________its astronauts into space.
In this university a medal with ten thousand dollars ________gains success in science and technology every two years .