If you sleep less than seven hours, you are three times more to catch a cold．
A. possible
B. certainly
C. probable
D. likely
网友回答
A. possible
B. certainly
C. probable
(答案→)D. likely
解析：如果你睡觉少于七小时你患上感冒的几率可能是三倍。表示“可能”且主语是“人”只能用likely，而 possible 或者probable的主语往往是it。故本题选D