自然状态下，输卵管堵塞，该女性则不能怀孕，原因是（）A．不能产生卵细胞B．精子与卵细胞不能结合成受精卵C．不能产生雌性激素D．受精卵无法着床-生物

更多内容推荐

• 下列关于结扎输卵管或输精管的说法中，正确的是（）A．能够有效阻止生殖细胞的结合B．会使精子或卵子不能形成C．会影响睾丸的生理功能D．会影响卵巢的生理功能-生物
• 胚胎大约在母体子宫中发育（）天．A．360天B．280天C．300天D．266天-生物
• 人类的生殖细胞、体细胞和受精卵中各含有多少个DNA分子（）A．生殖细胞23个体细胞46个受精卵23个B．生殖细胞46个体细胞46个受精卵23个C．生殖细胞23个体细胞46个受精卵46个D．生殖-生物
• 在人的生殖过程中，受精和胚胎发育的场所分别是输卵管和子宫．______．-生物
• 人类新个体的产生起始于（）A．精子与卵细胞结合B．产生精子和卵细胞的过程C．精子进入输卵管D．受精卵进入子宫-生物
• 下列有关生殖和发育的叙述中，不正确的是（）A．受精作用发生在女性输卵管里B．第二性征是在性激素的作用下出现的C．子宫是女性最主要的性器官D．胎儿通过胎盘和脐带与母体完成物质-生物
• 胎儿在母体内生活，氧气是（）A．通过胎儿的呼吸系统获得的B．直接从母体的血液中获得的C．通过胎盘从母体中获得的D．通过胎儿的消化系统获得的-生物
• 精子与卵细胞相遇在（）A．输精管B．输卵管C．子宫D．卵巢-生物
• 家兔的胚胎在母体子宫内发育时，不可能从母体内获得（）A．无机盐和维生素B．血细胞和消化液C．葡萄糖和氨基酸D．水和氧气-生物
• 下列属于生殖细胞的是①精子②卵细胞③受精卵④卵巢⑤睾丸[]A．①②B．③④C．②⑤D．②④-七年级生物
• 人类新个体的产生要经历由___________结合，通过_________发育形成新个体的过程。-七年级生物
• 胎儿从母体产出叫[]A．孵化B．分娩C．羽化D．出生-八年级生物
• 下图是子宫内的胎儿、胎盘和母体的关系图，请据图回答下列问题。(1)胎儿在母体的[]__________中发育，生活在其内半透明的液体__________中，胎儿所获得的营养经过[]________-七
• 人的胚胎形成就可称为胎儿。[]-八年级生物
• “十月怀胎，一朝分娩”，感谢母亲给了我们生命。在280天的辛苦孕育过程中，母亲时刻通过下列哪一器官或结构为胚胎发育提供养料和氧气[]A．子宫B．输卵管C．胎盘D．卵巢-八年级生物
• 人和其他动物的发育起点是[]A．精子B．卵细胞C．受精卵D．新生儿诞生-八年级生物
• 生命的产生是从下列哪项开始的？[]A．受精卵B．胎儿-七年级生物
• 阅读理解。 People realize that, although animals may not have the same intelligence (智力) as human beings,
• 阅读理解。Dear Lan Lan,I'm now writing to you at Hartsop, a village in the Lake District, a place to
• 阅读理解。People often say, "Even without stepping out of my house I know all that has been happenin
• 完形填空。 We find different kinds of animals in the world. Some animals, such as tigers and lions live i
• 阅读理解。 When you want to go shopping, decide how much money you can, spend for new clothes. Think abou
• 阅读理解。 Department stores sell ready-to-wear clothing, which is also called ready-made clothing. Such
• 阅读理解。 I'm lying on my back in my grandfather's orchard (果园), looking up at the branches ab
• 阅读理解。 In the past, American families tended to be quite large. Parents raising five or more children
• 王梅发现她家新买的白炽灯用过一段时间后，在相同电压下发光时要暗一些，从物理学的角度看是因为灯发光时，温度升高，灯丝发生了现象（填物态变化的名称），使灯丝变细，导致灯-八年级物理
• 下列物态变化中属于升华现象的是（）A．夏天，冰棍冒出的“白气”B．放在衣柜里面的樟脑丸变小了C．花盆中潮湿的泥土变干了D．冬天，湖面封冰-八年级物理
• 如图1所示的各种自然现象的形成过程，属于凝华的是-九年级物理
• 雨、露、霜、冰都是自然界中水的“化身”，其中由空气中的水蒸气凝华而成的是A．雨B．露C．霜D．冰-八年级物理
• 衣橱中的卫生丸时间长了会变小，原因是发生了（填写一种恰当的物态变化）；冰箱冰冻层的雪糕上沾有霜花，原因是发生了．-八年级物理
• 阅读理解。Dear Sir, I'm writing to complain about the service offered by your company. I told your
• 阅读理解。 In the past, when people had problems, they went to their families or friends to get advices.
• 阅读理解。 Do you know something about the holiday camps in Hong Kong? The students in Hong Kong used to
• 阅读理解。Dear Sir, I have to travel every day from Souk Road to the airport. Two buses travel along thei
• 阅读理解。 A child's birthday party should be one of the most fun events of the year, for the birthd
• 阅读理解。 Anybody running a company knows that a well-planned conference can greatly improve performance
• 任务形阅读。 We all look forward to vacations. They can give our daily life colorful meaning. Moreover, in
• 完形填空。 The morning in London was wet, wet, wet. I had to check out from the1before noon, and then I w
• 阅读理解。 My topic today is the Internet. It was prompted (引出) by the first letter, which I am unable to
• 阅读理解。 Let children learn to judge their own work. A child learning to talk does not learn by being c
• 完形填空。 The eyes are one of the most expressive instruments of body language. Keith, seventeen, from M
• 下面是一篇应用文及其应用场合的信息，请阅读下列应用文和相关信息，并按照要求匹配信息。选项中有一项是多余选项。阅读下面六款手机的介绍，选出符合各人需求的最佳款式。 -高二英语
• Children and teenagers who spend lots of time in front of screens---especially TVs---are easier to g
• Climate change could affect food supplies, water resources, human health and homes.If greenhouse gas
• Nuclear power’s danger to health, safety, and even life itself can be summed up in one word: radiati
• Health experts are calling for action to increase cancer care and control in the developing world. A
• As we get older, the fear of not having a good memory grows for many people. A lot of people 48that
• When it comes to eating smart for your heart, stop thinking about short-term solutions and simplify
• Overweight has been a great concern for some people. In an attempt to keep normal weight, people hav
• Since 1950, the amount of information about the nutrition of food has increased by nearly 900 percen