As a teacher , we should try to _____ it ____ to our students how helpful a correct learning method is .
— What on earth are the police busy with? — They have been looking into how the plane crash _______.
— How long is it _____ you picked up your badminton training? — It was not until my finance became better in last December _____ I started the training.
It was Mr. Zhang that helped us out of the trouble. Without his help, we ______ it so easily.
We should well balance our work and relaxation, and only by doing that, as everybody would agree , ______ a good state of mind.
— What does the notice on the wall say? — “No person _____ take books out of the reading room; otherwise he _____ be fined.”