下列有关实验的评价正确的是（　　）A. 点燃某可燃物，在火焰上罩一个冷而干燥的烧杯，烧杯的内壁有水雾

您可能感兴趣的试题

• 1生命伦理学在哪项基础上形成的A、临床医学与医德学B、伦理学与医学C、生命质量论与生命价值论D、伦理

  生命伦理学在哪项基础上形成的

  A、临床医学与医德学

  B、伦理学与医学

  C、生命质量论与生命价值论

  D、伦理学与生命质量论

  E、伦理学与生命科学

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做
• 2短周期元素A、B、C、D的原子序数依次增大.A原子的最外层电子数是内层电子数的2倍，元素B在同周期的
  短周期元素A、B、C、D的原子序数依次增大.A原子的最外层电子数是内层电子数的2倍，元素B在同周期的主族元素中原子半径最大，元素C的合金是日常生活中常用的金属材料，D位于第ⅥA族.下列说法正确的是（　　）A. 元素A、B的氯化物具有相同类型的化学键B. 元素A与氢形成的原子比为1：1的化合物有很多种C. B、C、D的最高价氧化物对应的水化物能相互反应D. 原子半径：D＞B＞C＞A
  
  点击查看答案进入在线练题题不想做，我帮你做
• 3规定的观察期内某病患者中因该病而死亡的频率是A.发病率B.患病率C.某病病死率D.某病死亡率E.治愈

  规定的观察期内某病患者中因该病而死亡的频率是

  A.发病率

  B.患病率

  C.某病病死率

  D.某病死亡率

  E.治愈率

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做
• 4The research carried out in eight countries______.A．reveals the relationship between sleep

  The research carried out in eight countries______.

  A．reveals the relationship between sleep problems and age

  B．provides evidence that lack of sleep affects people"s health

  C．puts forward the theory that sleep problems are a kind of disease

  D．proves that sleep problems will lead to smoking and poor diet

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做
• 5求原因.w,x,y,z,是原子序数依次增大的同一短周期元素,w、x是金属元素,y、z是相邻的非金属元
  求原因.w,x,y,z,是原子序数依次增大的同一短周期元素,w、x是金属元素,y、z是相邻的非金属元素,y的低价氧化物通入z单质的水溶液中能发生反应生成两种强酸.w、x、y、z各是什么?w：Na.x：Al.y：S.z：Cl
  
  点击查看答案进入在线练题题不想做，我帮你做
• 6求高中化学常见的方程式
  求高中化学常见的方程式
  
  点击查看答案进入在线练题题不想做，我帮你做
• 7According to the passage, what problem does the recent research find？A．Sleep shortage has

  According to the passage, what problem does the recent research find？

  A．Sleep shortage has become a worldwide problem.

  B．Developed nations don"t pay enough attention to sleep.

  C．Sleep problems are more serious in developing countries.

  D．Lack of sleep is more obvious in developed countries.

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做
• 8American students usually get their high school diploma at the age of______.A．12B．17C．20D．

  American students usually get their high school diploma at the age of______.

  A．12

  B．17

  C．20

  D．24

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做
• 9高中化学所有重点方程式 帮忙写详情点 谢谢!
  高中化学所有重点方程式 帮忙写详情点 谢谢!
  
  点击查看答案进入在线练题题不想做，我帮你做
• 10What responsibilities do states have concerning education？A．They must decide what certific

  What responsibilities do states have concerning education？

  A．They must decide what certificate teachers should have.

  B．They must pick out the suitable textbooks for students.

  C．They must make sure every child can receive education.

  D．They must provide enough funds for their schools.

  请帮忙给出正确答案和分析，谢谢！

  点击查看答案进入在线练题题不想做，我帮你做