阅读下面短文，从短文后各题所给的四个选项(A, B, C和D）中，选出可以填入空白处的最佳选项飞并在答题卡上将该项涂黑。
There are times when people are so tired that they fall asleep almost anywhere. We can see there is a lot of sleeping on the bus or train on the
_（1）____home from work in the evenings. A man will be
__（2）____the newspaper, and seconds later it
__（3）___ as if he is trying to
___（4）__it. Or he will fall asleep on the shoulder of the stranger
___（5）__ next to him.
___（6）___ place where unplanned short sleep
__（7）__ is in the lecture hall where a student will start snoring（打鼾）so
___（8）____that the professor has to ask another student to
___（9）___ the sleeper awake. A more embarrassing（尴尬）situation occurs when a student starts falling into sleep and the
___（10）___ of the head pushes the arm off the
___（11）___, and the movement carries the
__（12）___ of the body along. The student wakes up on the floor with no
___（13）___ of getting there. The worst time to fall asleep is when
__（14）___ . Police reports are full of
___（15）___ that occur when people fall into sleep and go
__（16）____ the road. If the drivers are
___（17）____ , they are not seriously hurt. One womanˈs car,
___（18）____ , went into the river. She woke up in four feet of
__（19）____ and thought it was raining. When people are really _
__（20）_____,nothing will stop them from falling asleep -- no matter where they are.