题干

农科所技术员研究温度对某蔬菜新品种产量的影响,将实验结果绘制成如下曲线。据此提出以下结论,你认为合理的是(  )

A:光合作用酶的最适温度高于呼吸作用酶的最适温度

B:光照越强,该蔬菜新品种的产量越高

C:阴影部分表示5~35 ℃时蔬菜的净光合速率小于零

D:温室栽培该蔬菜时温度最好控制在25~30 ℃

上一题 下一题 0.0难度 选择题 更新时间:2013-03-26 11:05:19

答案(点此获取答案解析)

D

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?
                                                                             

同类题4

阅读下面的文字,完成下列小题。

《红楼梦》的开篇神话

    《红楼梦》是由一个神话故事开端的。说的是大荒山无稽崖下,有一块女娲补天时未被采用的石头,幻化为神瑛侍者,每天用甘露浇灌三生石畔上的一颗绛珠仙草,后来仙草修成女身,愿把一生所有的眼泪还他的情。因此一事,便引出一部悲金悼玉的《红楼梦》来。

    故事虽然说来荒唐无稽,但是任何神话都有其尘根俗缘。曹雪芹编造的这个神话故事,毫无疑问也是有其现实的基础的。那么,《红楼梦》中的这块顽石,到底生于何方何地呢?作者说是本于“大荒山,无稽崖”,用脂砚斋的话来说,就是“荒唐也,无稽也”,亦即是无可稽考之处。在我看来,这是作者和批者有意让人处于扑朔迷离之中,它应当是真有其处的。依据相关材料揆情度理,我认为,它应当是我国东北部的长白山。在远古时代,人们便称此为“大荒山”。我国第一部地理学著作《山海经》中记载:“大荒之中有山,名不咸,在肃慎之国。”肃慎,位于我国东北的东北部;不咸,蒙语即神仙的意思;不咸山,即仙山。长白山天池之畔有一天豁峰,山峰形状奇特。山石巨大,其中最大的一块,便名曰“补天石”。

    “绛珠仙草”又是什么呢?我认为,它即是长白山上的名贵特产人参。人参常被称为“神草”或“仙草”,长着对生的绿叶,绿叶中间挺立着一株长长的花柱,柱上结着一串串红宝石似的珠果,颜色绛红绚丽,形状如同南国红豆,晶莹剔透。这样看来,这个“绛珠仙草”不是人参又是什么呢?

    “神瑛侍者”呢?他似是“神鹰”的谐音。很早以前,满人中间流传一个神话:有三个仙女在长白山天池里洗澡,有一只神鸟(也有称说神鹰的)噙来一颗绛红的仙果放到最小的仙女佛库伦的衣服上,仙女吞下红果后生个男孩,便是清世祖先布库里雍顺。因此,神鸟(或神鹰)与绛红朱果的兰因絮果,恩恩怨怨,早就缔结在三生石畔了,曹雪芹只不过是将其巧妙地改造了一番,且完全不露一点痕迹。

    为什么曹雪芹要用这么一个神话故事,来牵引出这部百年望族的兴衰史呢?曹雪芹先人早在明万历年间迁居沈阳附近,加入旗军正白旗。他们为清室开创基业,屡立卓越功勋。因此曹雪芹用这么一个神话故事开篇,这与他绵绵不绝的寻根怀旧思恋有着直接的关系。曹雪芹生于末世,当年随同清室一同入关的八旗子弟,个个都是声名显赫,唯独他结庐在荒凉的西郊荒野村,穷困潦倒,怎能不产生“娲皇只用了三万六千五百块、单单剩下一块未用”的慨叹呢?

    曹雪芹在一首《画中诗》中说:“爱此一拳石,玲珑出自然。溯源应太古,堕世又何年?有志归完璞,无才去补天。不求邀众赏,潇洒做顽仙。”这里明明点出这块顽石的来历,它的根源本来尊贵,详溯其源当是出自太古的大荒山(即长白山)山巅,遥想当年是何等的荣耀,只是今日才蒙蔽尘埃,埋没于蓬蒿之中。现虽欲返璞归真,但又不能去攀结那些豪门权贵,只能是“自怨自愧,日夜悲哀”而已!并于万般无奈之中,才求诸笔墨文字,冀图得到诸如空空道人之类的人去传述其一番历历可数的心迹罢了。