在马蛔虫的卵裂中,不产生染色体消减的细胞将形成()。 A.黄色新月 B.原生殖细胞

题型:单项选择题

问题:

在马蛔虫的卵裂中,不产生染色体消减的细胞将形成()。

A.黄色新月

B.原生殖细胞

C.极叶

D.体细胞

考点:发育生物学发育生物学题库
题型:单项选择题

单位因特殊情况需坐支现金的,在支付时应报经开户银行审查批准。( )

题型:单项选择题

阅读理解。

     "Our aim is to take our art to the world and make people understand what it is to move,"  said David

Belle, the founder of parkour (跑酷).

     Do you love running? It is a good exercise, yet many people find it boring. But what if making your

morning jog a creative one? Like jumping from walls and over gaps, and ground rolls? Just like the James Bond in the movie Casino Royale? Bond jumps down from a roof to a windowsill and then runs several

blocks over obstacles on the way. It is just because of Bond's wonderful performances that the sport has

become popular worldwide.

     Yes, that's parkour, an extreme street sport aimed at moving from one point to another as quickly as

possible, getting over all the obstacles in the path using only the abilities of the human body. Parkour is

considered an extreme sport. As its participants dash around a city, they may jump over fences, run up

walls and even move from rooftop to rooftop.

     Parkour can be just as exciting and charming as it sounds, but its participants see parkour much more

than that.

     Overcoming all the obstacles on the course and in life is part of the philosophy (理念) behind parkour. This is the same as life. You must determine your destination, go straight, jump over all the barriers as if in parkour and never fall back from them in your life to reach the destination successfully. A parkour lover

said, "I love parkour because its philosophy has become my life, my way to do everything."

     Another philosophy we've learnt from parkour is freedom. It can be done by anyone, at any time,

anywhere in the world. It is a kind of expression of trust in yourself. It is only a state of mind. It is when

you trust yourself that you earn energy.

1. Parkour has become popular throughout the world because of _____.

A. its founder, David Belle

B. the film, Casino Royale

C. its risks and tricks

D. the varieties of

2. The underlined word "obstacles" in Paragraph 2 is closest in meaning to "_____".

A. streets  

B. objects  

C. barriers  

D. roofs

3. Which of the following is true of parkour?

A. It challenges human abilities.

B. It is a good but boring sport.

C. It needs special training.

D. It is a team sport.

4. Which of the following is the philosophy of parkour?

A. Sports and extremes.

B. Excitement and freedom.

C. Dreams and success.

D. Determination and freedom.

题型:单项选择题

一轧件经若干道次轧制后,成为断面积为64mm2的方坯,下一道次为椭孔,经椭孔轧制后断面尺寸为b×h=13×5.2(mm×mm),求此椭孔宽展系数为多少?

题型:单项选择题

按照《热水锅炉安全技术监察规程》的规定,为保养锅炉,对备用或停用锅炉应采取哪些措施?

题型:单项选择题

男性,62岁,突然出现剧烈头痛和呕吐8小时。无发热,否认高血压史。体检:神清,体温36.9℃,血压16.5/10kPa,右侧瞳孔直径3.5mm,对光反应消失,上睑下垂,眼球向上、下及内侧运动不能。颈项强直,克氏征阳性。CT示脑正中裂及右大脑外侧裂、枕大池呈高密度影。该患受累的颅神经是

A.右侧滑车神经

B.右侧三叉神经

C.右侧动眼神经

D.右侧外展神经

E.右侧面神经

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