What does PM 2.5 mean—It’s a professional ________ indicating the condition of air pollution.

doseit take to get to the airport from here — It takes half an hour.

Is this the watch you wish to _____?

More than 200 million people in China suffer high blood pressure, and 70% of them are unaware of the fact ______they have the illness.[ ]

The world will be different, and we will have to be prepared to ______ the change.