_____ you can understand how the human body woks, you need to have some knowledge of chemistry
It’s cold outside.________your sweater before you go out.
—How long does it take to get to the airport?—Forty minutes.But it’s foggy today.I’m not sure________the highway will be closed soon.Let’s set off earlier.
—You study________hard________you’re sure to pass the exam.—Thank you for saying so.
—Who broke the window?—________.A strong wind broke it last night.
Many students said that they were willing to work hard to make their dreams________true.