I don’t know what to do next.I ___ ___ ___ what to do next.
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)
You can’t pass the entrance without a p_____