在测量误差的分类当中,误差大小和符号固定或按一定规律变化的是()。A.系统误差 B.

题型:单项选择题

问题:

在测量误差的分类当中,误差大小和符号固定或按一定规律变化的是()。

A.系统误差

B.随机误差

C.粗大误差

D.绝对误差

考点:仪表工考试热工仪表检修工(高级)热工仪表检修工(高级)题库
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(1)学校食堂的采购单上列出以下五种食品:①草鱼;②牛奶;③玉米;④鸭肝;⑤黄瓜.这五种食品中,含有的营养素是______;

(2)下表为钙、铁、锌、碘四种元素的食物来源,由此判断上述五种食品中含有的元素符号为______;

元素种类食物来源

奶类、绿色蔬菜、水产品、肉类、豆类

肝脏、瘦肉、蛋、鱼、豆类、芹菜

海产品、肝脏、瘦肉、奶类、豆类、小米

海产品、加碘盐

(3)下列关于钙、铁、锌、碘四种元素的说法中,正确的是______(填字母序号);

A.钙、铁属于常量元素             B.钙主要存在于人体的骨骼和牙齿中

C.锌是甲状腺素的重要成分         D.补铁有利于维持人体内的水分

(4)在人体组织里,每克葡萄糖在酶的作用下缓慢氧化,约放出15.6kJ能量.现有一名学生行走2km,消耗了312kJ的能量,假设能量全部由葡萄糖提供,则该学生体内消耗葡萄糖约______g.

题型:单项选择题

下列叙述中,错误的是[ ]

A.离子化合物中可能含有非极性键

B.分子晶体中的分子内不含有离子键

C.原子晶体中可能含有非极性键

D.分子晶体中的分子内一定有共价键

题型:单项选择题

阅读下面短文和问题,根据短文内容,在答题纸相应题号后的横线上写下相关信息(不多于五个单词),完成该问题的回答。答语要结构正确,书写工整,字迹清楚。

These days, people are concerned about the growing number of kids who are overweight. The number of overweight kids has increased a lot over the last 30 years. Today, more than 15% of the kids aged 6 to 19 are overweight.

In a recent study in the USA, 1,168 boys and girls were asked about the problem. More than half of them said too many girls were overweight.

What does “Overweight” Mean?

Most people who are overweight have too much body fat. The person who is overweight weighs more than is healthy. Being overweight can lead to health problems, like heart disease. Overweight kids also may feel sad about the way they look. Sometimes they get laughed at by other kids and it is harder for overweight kids to make friends.

Why Are Some Kids Overweight?

When asked why some kids were overweight, many kids said it was because overweight kids didn’t exercise enough or eat right. Others said that kids were overweight because fast food restaurants serve the wrong foods or it’s a problem of genes.

How Are the Kids Trying to Lose Weight?

Plenty of kids said they have tried to lose weight and they have been trying to do the following:

● go on a diet – 17%

● eat healthy and exercise – 64%

● eat out less – 4%

● take medicine – 5%

It’s great that kids are thinking about weight problems and are trying to solve them. It’s like putting together a difficult puzzle. Understanding that there’s a problem is one piece. Understanding what causes kids to be overweight is another. And knowing that eating healthy and exercising are the best ways to fix the problem is a very important piece.

小题1:How do overweight kids feel about the way they look?

___________________________________________________________________

小题2:Some kids have tried to lose weight. What have 64% of them been trying to do?

___________________________________________________________________

小题3:What is the passage mainly about?

___________________________________________________________________

题型:单项选择题

110配线箱规格为500对的高度是()。

A.450mm

B.650mm

C.850mm

D.1050mm

题型:单项选择题

某道路工程划分为4个施工过程、5个施工段进行施工,各施工过程的流水节拍分别为6天、4天、4天、2天。如果组织加快的成倍节拍流水施工,则流水施丁工期为()天。

A.40

B.30

C.24

D.20

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