题干

函数y=log
1
3
(x2﹣ax+3)在[1,2)上恒为正数,则a的取值范围是(  )

A:22<a<23

B:22<a<72 

C:3<a<72

D:3<a<23

上一题 下一题 0.0难度 选择题 更新时间:2012-04-10 11:21:50

答案(点此获取答案解析)

D

同类题2

阅读下面的文字,完成后面题。

梁启超面面观

    梁启超很欣赏孔子所说的“智者不惑,仁者不忧,勇者不惧”,并以此自励,大智、大仁、大勇的梁启超为后人铭记。

    在近现代学术史上,梁启超的成就和影响都非常大。他留下了1400多万字的著述,在33年的著述生涯中平均每年要写40多万字,他撰写《陶渊明年谱》三日而成,他用一昼夜完成《戴东原先生传》,他的著作中最有名的是《清代学术概论》,本是为别人作序,结果一发而不可收,用15天写成一部6万字的著作……而这一切都是在他自戊戌以后的政治运动无不参与的情况下完成的!梁启超的治学领域极其广泛,他的著作涉及哲学、史学、文学、图书馆学、社会学等诸多学科。在学术研究上,他不动手则已,一动手便有极大的格局放在那里,不管能否成功。他喜于将某一件事物、某一国学术做一个通盘的打算,进行大规模的研究,永不肯安于小就,做一种狭窄专门的精密工作。

    梁启超在《新民说》中把敢于进取冒险作为新国民应具备的品德之一,他一生中至少有三次冒险,尤以1916年只身劝广东都督龙济光反袁护国最为惊险——此前梁启超的好友汤觉顿前往劝说摇摆不定的龙济光时,竟被龙济光的部下开枪打死。梁启超强压悲愤,冒险出马,与龙济光苦口婆心地谈了十几个钟头,龙济光当时表示心悦诚服,随后龙济光把他手下的军官聚集起来给梁启超开欢迎会,这帮军官个个拖枪带刀,一开始还客客气气,酒过三巡,凶相毕露。梁启超一看耐心说服已无可能,便索性豁出去了,对龙济光吼道:“我单人独马手无寸铁跑到你千军万马里头,我本来不打算带命回去。我一来为中华民国前途求你们帮忙,二来也因为我是广东人,不愿意广东糜烂,所以我拼着一条命来换广州城里几十万人的安宁,来争全国四万万人的人格。既已到这里,自然是随你们的便,要怎样便怎样!”梁启超滔滔不绝地演说了一个多钟头,声音之大就像打雷,一面说一面不停地拍桌子,把桌子上的玻璃杯震得叮当作响,一时举座皆惊,左右皆靡。梁启超这一吼,不仅救了自己一命,也逼着龙济光宣布独立。

    粱启超一生经历过多次大风大浪,但他成不了一个老练的政治家,这与当时的政局有关,也是他的性格使然。他特别看重趣味,曾说:“有人问我,你的人生观拿什么做根底?我便答道‘拿趣味做根底’,凡人必常常生活于趣味之中,生活才有价值。”“我所做的事常常失败——严格地可以说没有一件不失败——然而我总是一面失败一面做,因为我不但在成功里头感觉趣味,在失败里头也感觉趣味。”梁启超的学问涉及面广,就是因为他的兴趣特别广泛。他曾对子女说:“我是学问趣味方面极多的人,我之所以不能专积有成者在此,然而我的生活内容,异常丰富,能够永久保持不厌不倦的精神,亦未始不在此。我每历若干时候,趣味转过新方面,便觉得像换个新生命,如朝旭升天,如新荷出水,我自觉这种生活是极可爱的,极有价值的……”

    梁启超一生多变,世所共知。他的多变颇遭时人及后人诟病。有人认为他一生所为学问除文学外都无大价值,不过于初学者有启迪之用,为他学问不能精深而感到惋惜;有人说他政治上“反复无常”——与康有为始合终分,与孙中山合作又对抗,对袁世凯先拥后反。梁启超晚年对自己的学生说,他是有中心思想和一贯主张的,绝不是望风转舵、随风而飘的投机者。郑振铎认为,梁启超最伟大之处,最足以表现他的光明磊落的人格之处便是他的“善变”。他的“屡变”,他的变不过是他变他的方法而已,他的宗旨、他的目的并未变,那就是爱国。

(选自《梁启超:趣味人生》,有删改)

同类题3

阅读下面材料,然后从各题所给的四个选项中选出一个最佳答案。

    Daniel Olin was 11 years old when his parents moved to Canada. He liked his new school and made friends there, but then things at home started to change. His mum and dad began to argue and the arguments got worse and worse until one day, Daniel's mum left. With his father working long hours, Daniel felt very lonely and very unhappy. He wanted to escape, to run away. And that's what he did.

    Very early one terribly cold morning when the snow was deep on the ground, he packed a bag with some clothes, some chocolate and a map of Canada and set off to a forest. He ran and ran until he could hardly breathe. His feet were heavy with the snow but he still walked on through deep snow, not even watching where he was going.

    Then, disaster struck. A rock hidden by the deep snow caught his feet and Daniel fell to the ground. He had broken the bone. He was very cold and was starting to feel tired, but he knew that if he fell asleep in the snow, he would certainly die from the cold.

    A tree shook ahead. From within the branches, a pair of yellow eyes watched Daniel. The puma had been following him. A puma is a large wild cat with claws that could tear. Daniel into pieces. But instead of moving in for the kill, the puma walked up to Daniel and lay across his chest, arms and legs. Daniel was too frightened to move, but soon the warmth of the animal reached Daniel and he began to feel better. From time to time, the puma pressed his muzzle against Daniel and rocked his head gently. Clearly, the puma knew that Daniel must not fall asleep. This animal should have been a real danger to Daniel and yet the boy began to feel safe.

    They remained like that for several hours until Daniel and the puma heard voices. The rescue team had found them.