When we __________ (呼吸), we draw air into our lungs.
How did your mother r_____ to the news? Did she get very angry?
Those scientists are _____(探索) all possible ways to cure the disease.
Have you ever been s_____ in a traffic jam?
They have found the————(解决办法) to the traffic problem.
There are four underground lines in Beijing, and several lines are under _______(建设)