China ________ rapid economic development and political stability over the past three decades, but with them ________ some social problems.
Life is like a long race ____ we compete with others to go beyond ourselves.
Since when has ____ been any of your business what I do?
We walked as fast as we could,____ to catch the 9:30 train.
—See the gathering clouds outside? Please take this umbrella with you. — .
Scientists hope to____soon in their fight against heart disease.