题干

设函数f(x)在R上可导,其导函数为f′(x),且函数y=(1﹣x)f′(x)的图象如图所示,则下列结论中一定成立的是(  )

A:函数f(x)有极大值f(2)和极小值f(1)

B:函数f(x)有极大值f(﹣2)和极小值f(1)

C:函数f(x)有极大值f(2)和极小值f(﹣2)

D:函数f(x)有极大值f(﹣2)和极小值f(2)

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D

同类题5

                                                                                      The Price of a Dream

    I grew up poor. We had little money, butplenty of love and attention. I understood that no matter how poor a person was, they could still afford a dream. My dream was athletics.

    By the time I was sixteen, I was good at baseball and football. My high-school coach was Ollie Jarvis. He not only believed in me, but taught me the difference between having a dream and showing conviction(信念).

    One summer a friend recommended me for asummer job. This meant a chance for money in my pocket — cash for dates withgirls, certainly, money for a new bike and new clothes, and the start of savings for a house for my mother.

    Then I realized I would have to give up summer baseball to handle the work schedule, and that meant I would have to tell Coach Jarvis I wouldn't be playing. I was dreading(害怕)this, but my mother said: “If you make your bed, you have to lie in it.

    When I told Coach Jarvis, he was as madas I expected him to be. “Your playing days are limited. You can't afford to waste them,” he said.

   I stood before him with my head hanging, trying to think of the words that would explain to him why my dream of buying my mom a house.

  “How much are you going to make at this job, son?” he demanded.

  “Three twenty-five an hour,” I replied.

  “Well,” he asked, “is $3.25 an hour the price of a dream?”

    That question laidbare for me the difference between wanting something right now and having agoal. I devoted myself to sports that summer, and within the year I was drafted by the Pittsburgh Pirates to play rookie-league ball, and offered a $20,000 contract. I signed with the Denver Broncos in 1984 for $1.7 million, and boughtmy mother the house of my dream.