The government _____ air quality in urban areas from level one to five: excellent, fairly good,slightly polluted, poor and dangerous.A arranges B. classifies C. distributes D. divides
Mr Li who is in _____ charge of our class is very experienced.
He is a man of ____ and he had a lot of interesting ____ in his life.
I don’t think _____ possible to master a foreign language without much memory work and practice.
Work hard at your lessons, ______ you’ll fail the exams again.
He devoted all the time _____ his research .