构成DNA和RNA的糖是() A.二糖 B.五碳糖 C.六碳糖 D.多糖

题型:单项选择题

问题:

构成DNA和RNA的糖是()

A.二糖

B.五碳糖

C.六碳糖

D.多糖

考点:高中生物组成细胞的分子组成细胞的分子题库
题型:单项选择题

一只断灯丝的灯泡,摇接灯丝后使用,要比原来亮一些,这是因为灯丝的电阻   __(填“增大了”或“减小了”)

题型:单项选择题

女性,28岁。体检:发现ALT200U,HBsAg(+),拟诊乙型肝炎住院,病人向医生问及有关肝炎常识时,医生回答哪项不正确()

A.肝炎有甲、乙、丙、丁、戊之分

B.慢性活动性肝炎均由乙型肝炎病毒引起

C.慢性迁延型肝炎,一般不会发展为肝硬化

D.甲型肝炎无慢性带病毒状态

E.肝细胞癌发病与慢性乙型肝炎病毒感染有关

题型:单项选择题

完成句子

阅读下列各小题,根据每句后的汉语提示,用句末括号内的英语单词完成句子.

1. ____________________,we often pay attention only to the differences without noticing many

   similarities.(compare)

在比较不同的文化时,我们总是只注意到差异而忽略了许多相似点.

2. ____________________,huge quantities of good earth are being washed away each year.(with)

随着更多的森林被毁,每年有大量肥沃的泥土被冲走.

3. After a heated discussion at the meeting, most of the people ____________________.(build)

会议上一场热烈的讨论之后,大多数人都提倡修建更多的学校.

4.  I had no idea ____________________ the car accident took place.(that)

我不知道车祸到底是在哪儿发生的.

5. In order to save the energy, you should turn off the electric appliance ____________________ it.(so)

为了节约能源,只要你没有在用,电器都应该关掉.

6. The accident ____________________ of two people has been reported on the newspaper.(result)

导致两个人死亡的那场事故在报纸上报道了.

7. But for the note you left, I ____________________ close the door.(forget)

要不是你留下的那张便条,我就会忘记关门了.

8. Without the government's great determination, ____________________the miners wouldn't be able to come back to the ground after so many days.(that)

如果不是政府的极大决心,毫无疑问那些矿工也不可能在这么多天之后被救回地面.

9. Exercise, as well as a balance diet__________________your health. (difference)

运动和平衡的膳食对你的健康有重要的影响.

10. We might as well buy things made from recycled materials as possible as we can, because __________________to make things from new materials.(take)

我们应该尽可能购买那些用回收材料制成的商品,因为用新材料制造商品需要花费大量的能源.

题型:单项选择题

旋转式直流弧焊机主要由哪些部分组成?

题型:单项选择题

导致信息系统失败的因素很多,其中最主要的因素是()

A. 缺乏资金

B. 缺乏开发人员

C. 技术力量薄弱

D. 社会因素

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