煤炭生产许可证环境保护年检工作由哪个机构负责？

下面关于类和对象的描述中，错误的是（ ）。

A．类就是C语言中的结构体类型，对象就是C语言中的结构体变量

B．类和对象之间的关系是抽象和具体的关系

C．对象是类的实例，一个对象必须属于一个已知的类

D．类是具有共同行为的若干对象的统一描述体

Teddy Bears have been a very popular children’s toy for many years. Most adults can remember their first stuffed（填充玩具）bear, and over the decades these toys have become nearly a symbol of their childhood. However, children are not the only ones with whom these toys have become popular, as many adults make it a habit to collect these toys as well.

The Teddy Bear first became popular during the early 20th century and was associated with then President Theodore Roosevelt. The story can date back to a hunting trip that President Roosevelt had taken where he was invited to be the one to shoot a black bear that had been tied to a tree. Being a crazy outdoors lover and hunter, Roosevelt refused to kill the animal because he believed that shooting the helpless bear was unsportsmanlike and wrong. This story quickly spread through newspapers across the country, and in the end inspired the introduction of a stuffed toy called “Teddy’s bear”.

These toys became popular soon after first introduced, and within ten years, they were being produced by dozens of companies around the world. Within a generation, these stuffed bears were “the” toy to have, and have always been within children’s toy boxes ever since.

They are most often mass-produced in factories in order to keep up with the high demand.  However, there are still companies that take great pride in their handmade designs; and while handmade teddy bears are often preferred, they are also generally more expensive than their mass-produced ones.

Today, these bears and other similar toys generate well over a billion dollars a year in profits for the companies that make them. Walk through just about any toy store in America and you will find dozens of different teddy bears lining the shelves.

小题1:According to the passage, we can know President Roosevelt ______.

A．didn’t like hunting

B．enjoy being special

C．was not brave enough

D．was fair and respectable小题2:Compared with mass-produced teddy bears, the handmade ones ______.

A．don’t sell well

B．are of high quality

C．are more expensive

D．are preferred by adults小题3:From the last paragraph, the writer intends to show ______.

A．teddy bears are very popular

B．toys are loved by many companies

C．producing toys can earn more money

D．teddy bears are also enjoyed by adults小题4:What is the passage mainly about?

A．History of the Teddy Bear.

B．A popular toy — Teddy Bear.

C．Who made the first toy bear?

D．Profits Teddy Bear have made.

在下列复杂系统中，（）是最著名的一个系统。

A、宇宙

B、环境

C、生命

D、计算机

2008年10月6日，瑞典皇家科学院诺贝尔奖委员会宣布将2008年度诺贝尔生理学或医学奖授予德国科学家楚尔郝森和两位法国科学家巴雷一西诺希和路克一蒙塔尼埃。德国科学家因发现人 * * 淋瘤病毒引发子宫颈癌获此殊荣，两名法国科学家因发现人类免疫缺陷病毒获此殊荣。下列关于病毒的描述，正确的是（）

①病毒在基因工程中可用做载体，灭活的病毒在细胞工程中可诱导细胞融合，在免疫中可用做疫苗

②人 * * 淋瘤病毒繁殖的条件全部由子宫颈癌细胞提供

③乙肝病毒探针可迅速检出乙肝患者的乙肝病毒

④病毒与细菌的区别是无典型的细胞核，病毒遗传物质为DNA或RNA

A.①④

B.②③

C.①③

D.③④

影响弯管椭圆度的主要因素用哪些？