Was it 80 years before Christopher Columbus crossed the Atlantic ______ Zheng He hadsailed to East Africa?
The notice has been told everyone _______ a party will be held in the open air tomorrow.
The meeting ________ in the hall tomorrow is about environment protection.
_________ teachers are present today, and __________ them is 300.
— You don’t forget when we borrowed that reference book, do you? — I can’t remember now but ________ sometime last week?
Mr. Johnson complained to his doctor that he lacked energy, so his doctor advised him to ________running.