题干

如图所示为物质出入细胞的两种方式(黑点代表物质分子),则相关叙述正确的是(    )

A:与甲相比,乙方式的不同之处只是需要载体蛋白协助

B:与甲相比,乙方式的唯一不同之处是需消耗能量

C:使活细胞能按照自身之需逆浓度梯度吸入或排出物质的应是乙方式

D:小肠上皮细胞吸收维生素D应如乙图所示

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答案(点此获取答案解析)

C

同类题2

   Eileen Collins is the first woman ever chosen to be a spaceship pilot. She is also the first woman to command(指挥) a spaceship. Today she has flown more than 5, 000 hours in more than 30 kinds of airplanes.
   Talking about high school, she said, “I began reading all kinds of books about famous women pilots. These women went and flew into dangerous places. Their stories encouraged me.” In 1977 Eileen got a pilot’s license and the following year she graduated from university. She went into space in 1999 at the age of 43. She took with her the hopes and dreams of a nation of young people on the earth.
   Eileen is not only an astronaut but also a wife and the mother of a young daughter. She has short curly hair and friendly brown eyes. She met her husband, Pat, while they were together in the air force(空军).
   When she was named as the First Woman Spaceship Commander in 1998, Eileen smiled and said, “When I was a child, I dreamed about space. It was only a dream that I would be one of the astronauts someday. I hope all children will be encouraged to reach for their dreams, when they see I go into space. I believe dreams do come true!”  
____ How many hours has Eileen flown?
                                                                             
____ When did Eileen go into space?
                                                                             
____ What does Eileen look like?
                                                                             
____ Who did Eileen meet in the air force?
                                                                             
____ Did Eileen believe that her dream would come true?