题干

下列符合现代生物进化理论的叙述是(  )

A:物种的形成可以不经过隔离

B:生物进化过程的实质在于有利变异的保存

C:基因突变产生的有利变异决定生物进化的方向

D:自然选择通过作用于个体面影响种群的基因频率

上一题 下一题 0.0难度 选择题 更新时间:2018-04-18 05:04:44

答案(点此获取答案解析)

D

同类题3

完形填空

    The world always makes way for the dreamer

    When I was twelve years old, my father took me to see Zig Zigler. I remember sitting in that dark hall listening to Mr. Zigler1everyone's spirits up to the ceiling. I 2there feeling like l could do anything. When we got to the car, I turned to my father and said, "Dad, I want to3 people feel like that." My father asked me 4 I meant. "I want to be a motivational speaker just like Mr. Zigler." I replied. A(An)5  was born.

    Recently, I began seeking my dream of motivating others. 6  a four-year relationship with Fortune 100 Company 7as a sales-trainer and ending as a regional(地区的) sales manager, I left the company at the height of my8. Many people were9that I would leave after earning a six-figure income. And they wondered10I would risk everything for a dream.

    I made my 11 to start my own company and leave my worryingless position after12a regional sales meeting. The vice-president of our company made a13 that changed my life. He asked us, "If a god would offer you three wishes, what would they be?" After giving us a(an)14 to write down the three wishes, he then asked us, "Why do you need a 15 ?" I would never forget the power I felt at that moment. I realize that 16 I had accomplished in the past had prepared me for this moment. I was ready and didn't need a god's help to become a motivational speaker. A motivational speaker was17 .

    Having made that decision, I was immediately18 . One week after I gave notice, my husband was laid off from his job, and now we had no 19. But I held fast to my dream. The wonder really began to happen. In a short time my husband found a better job. And I was able to book several 20 engagements with new customers. I discovered the incredible power of dreams.

同类题4

阅读下面的作品,完成下列小题。

谁的心中不曾有过远方

    “世界那么大,我想去看看”,当微信朋友圈被北京的沙尘暴刷屏,这句话给人的“小清新”之感,更显强烈。近日,河南一位女教师这封“最有情怀”的“辞职申请”,引来无数人共鸣。

    念念不忘,必有回响。一句话撩动心弦,正是因为它以一种诗意的方式,说出了不少人心中的渴望。所谓“世界”,其实是相对日常生活的一种异质性存在。从朝九晚五的按部就班中跳出来,从办公桌边的循规蹈矩里跳出来,打破思维方式的条条框框,摆脱现实生活的患得患失,拥抱一个更广阔也更精彩的世界。即便这个世界可能只是一种美好的想象,但谁的心中没有激荡过一个远方?

    其实,一个正常的社会,应该是一个有着普遍稳定性的社会。这不仅会少一些可能引爆社会对抗的易燃点,也使每个人都能在其中找到自己的位置。对于“想去看世界”的辞职,虽然点赞者甚众,但真正能“从心动到行动”的,在这样的社会里不应该也不可能成为主流。毕竟,情怀不能当饭吃,甜点也不能当正餐。辞职的女教师去“看世界”了,更多的人却选择了留下来,在讲台上继续自己的事业,换个角度看,没去看世界者不才是这个社会的基石吗?

    说到底,渴望远方,还是因为现实的砝码更重一些,它让说走就走的旅行难以成行。黄土涵养农耕,农耕孕育家庭,数千年的中华文明,让生存状态的“稳定性”,成为这种文化所化之人最基本的诉求。学者认为中国社会有着“超稳定结构”,其实,从安土重迁的观念到家族聚居的方式,中国人的心灵世界又何尝不是如此?这或许也是一些稳定的职业有着很强吸引力的原因。在这样一种文化中,“现世安稳”是一种扯不断的心理牵挂、情感羁绊。

    站在这个层次上,或许更能理解“世界这么大,我想去看看”引来的共鸣。身处开放的环境、面对信息化的洪流,“世界”是个诱惑十足的词。然而,在竞争激烈、“压力山大”的社会中,面向大海的转身难以避免地遭遇更多艰难。“外面的世界很精彩,外面的世界很无奈”,或许,去世界看看的人们,终究还是要面对“娜拉出走之后”甚至“娜拉回来之后”的问题。“出门看世界”和“回到老地方”,成为当今中国人一组难以解开的心结,惟有在朋友圈里徒然羡慕着远方。

    “世界那么大,我想去看看”,看起来文艺腔十足的表达,背后是时代的发展、文化的演进,诠释着社会心理结构的变迁。其实,生活充实,何必别处?心有梦想,何必远方?过好每一天,走好每一步,未尝不是同样精彩的人生。

(摘自《人民日报》,有删减。)