It is time to call it a day.=现在到此为止。
                    举一反三
- The probability of receiving a 911 call on a university campus is the same every day. The probability of having received a 911 call on a single day does not change the probability of receiving a 911 call on any other day. Which of the following distributions would you use to determine the probability that a 911 call will be received next day?
 - I think the weather’s changing. Let’s call it ______. A: a day B: the end C: the time D: day
 - What do you announce to the tourists at end of the day when you come back to the hotel? A: morning call of the next day B: time and place for breakfast of the next day C: time and place of departure of the next day D: specific arrangement of the next day
 - Whenever you call me, I’ll come ( ) no time, day or night. A: at B: on C: in D: for
 - -How is the day going?- ___ A: You are welcome. B: Let's call it a day. C: Thank you very much. D: Pretty good.
 
