Once new difficulties _____ in our study, we should learn to use our brains to solve them.
Several hours later, with the help of the police, the students managed to escape from the dangerous place, _______.
That light rail transit line(轻轨), __ _in July 2009 and ___ in 2012, will be China’s longest light rail transit line in history.
Annie often tells her classmates ______ at the remote school in the mountain area and what she has done there as a volunteer.
.—IgotanemailfromSusan, ______saidUshewasgoingabroadforsightseeing. —Fantastic!That’swhatshehasbeendreamingof.
--- Remember the first time we ______ , Peterson? --- Of course, I ______ . We’ve been close friends ever since.