问题
选择题
If you sleep less than seven hours, you are three times more to catch a cold．
A．possible
B．certainly
C．probable
D．likely
答案
答案：D
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