— Why are you so popular with your students?— As a teacher, I seldom give my students so difficult a problem ____ they cannot work out.
He did not regret saying what he did but felt that heit differently.
Nowadays some protective parents want totheir kids from every kind of danger, real or imagined.
to sunlight for too much time will do harm to one’s skin.
They appearedme, so I had to explain to them.
If China’s space technology has achievedbreakthrough in this field, it really is amazing wonder.