I remember _____the factory owed a small workshop and two machines.
No student ________ go out of the school campus after 10:00 at night without permission according to the school regulations.
Only after one loses something ________ how precious it is.
Life is like riding a bicycle. _____ your balance, you must keep moving.
Peter, though a green hand, has earned not only the trust of his fellow workers but also ________ of his boss.
A few stars from the entertainment industry, such as Ke Zhendong and Fang zuming, have recently been arrested, which shows that drug taking is becoming _____ increasingly serious threat to society.