关于精子变形的叙述错误的是 [ ] A.线粒体退化消失 B.高尔基体发育为头部的

题型:选择题

问题:

关于精子变形的叙述错误的是 [ ]

A.线粒体退化消失

B.高尔基体发育为头部的顶体

C.中心体演变为精子的尾

D.细胞核变为精子头部的主要部分

考点:生物的生殖和发育
题型:选择题

司马光说:“介甫文章节义,过人处甚多。但性不晓事,而喜遂非。致忠直疏远,谗佞辐辏。”司马光所说的“谗佞”是指                                           (  )

A.政府中的贪官

B.拥护变法的人

C.反对变法的人

D.变法中得益的农民

题型:选择题

战术性资产配置策略是根据资本市场环境及经济条件对资产配置状态进行动态调整,从而增加投资组合价值的积极战略。()

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科学家在地球轨道外侧发现了一颗绕太阳运行的小行星,经过观测该小行星每隔t时间与地球相遇一次(即距离最近),已知地球绕太阳公转半径是R,周期是T,设地球和小行星都是圆轨道,且在同一个面同向转动,求

(1)太阳的质量

(2)小行星与地球的最近距离.

题型:选择题

It was graduation day at the university where I work and a beautiful day quite unlike the first graduation I attended as a young professor.On that cold day years ago, as we watched the students walking into the hall, one of my colleagues turned to me and said, "Graduation will be one of the happiest and one of the saddest time of your life." At my inquiry, he answered, "Because the students you have gotten to know have to leave."

As years went by, my previous confusion about my colleague's words no longer existed.When I came across naughty students, I have had to rethink why I chose to be a teacher.It obviously isn't the money.Once a former computer science student of mine called me, asking me if I wanted to have a change.He was working at Nintendo Corporation.His salary was higher than my current one, though I have more education and have worked for over a decade.With my programming skills, he said he could get me hired.I thanked him, but declined his kind offer.

A few days before this current graduation, while working on final grades, I found a note a student had slipped in with her homework.She thanked me for being her teacher and said the things she had learned in my class—not about math, but about life—would be things she would remember long after the math skills had faded away.As I finished reading, I remembered why I had become a teacher.

Now, on this sunny graduation day, as I again observed the sea of blue hats and gowns, I did so with renewed dedication (奉献) and a deeper sense of satisfaction—I will always be grateful that I am a teacher.

小题1:Hearing his colleague's description of graduation for the first time, the author __________.

A.quite agreed with his colleague

B.was very puzzled

C.thought it very funny

D.was very sad小题2:The computer science student called up the author because he___________.

A.wanted to inform the author of his present job

B.tried to persuade the author to work with him

C.wanted the author to share his joy and satisfaction

D.thought the author wasn't fit to be a teacher小题3:The underlined part “blue hats and gowns” refers to___________.

A.university colleagues

B.graduates' clothes

C.life memories

D.decorations in the hall小题4:The author wrote this passage to __________.

A.express his devotion to being a teacher

B.compare two different graduation ceremonies

C.talk about the meaning of graduation

D.give advice on how to be a good teacher

题型:选择题

面角代表()。

A.上颌的凸缩程度

B.下颌的凸缩程度

C.面部的突度

D.下中切牙的突度

E.上中切牙的突度

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