The children are giving their classroom a good cleaning, ___ are sweeping; ___ are mopping.
As a result of the fog haze weather, nowadays many people are longing to live ______ the air is fresher.
—I thought you ______ for vacation tomorrow. —I had planned to, but I have a very important meeting to attend tomorrow.
As President Xi Jinping put it in Moscow on Saturday, China’s development creates more ______ than threats.
More than 800,000 Chinese overseas students have returned in the last five years, with the annual number ______ by an average rate of 36 percent each year.
For most informal dinners, you should wear comfortable and ______ clothes.