Why can your neighbor know so much about London?—He ____ have been there before.

Are these her rulers —-_____________.

Ling Feng won the first prize in the national English competition and I’m glad that her efforts at last ________.

I usually go to school _______ bike.

China’s goal of 7.5 percent GDP growth this year, though moderate in comparison with previous rates, is not cause for concern since it could still generate ________ volume wealth.