The researchers found clear and convincing evidence _______ happiness is the key when it comes to better health and longer lives.
It was 80 years before Christopher Columbus crossed the Atlantic _____ Zheng He had sailed to East Africa.
Whenever he was asked why he was late for class, he would answer carelessly, always the same thing.
The old clock needs every day, otherwise it will stop working.
—I feel so nervous about the coming college entrance examination. —________. You have been studying very hard.
Our teacher requested all of us _________ late for class.