Had they known what was coming next, they ___________ second thoughts.
Sometimes the balance in nature is ______ , resulting in a lot of unforeseen effects.
You _____only half the price ,how would the seller sell the book to you ?
I tried my best to keep calm in face of the students, but the sweat on my forehead _____ me____.
After retirement, Mr. Mike ______ drawing, which he had always loved but had not had time for.
You’d better ______ some hot water into the teapot in case the tea cools down.