简述法律文书的概念。

D

Any mistake made in the printing of a stamp raises its value. A mistake on one inexpensive postage stamp has made the stamp worth a million and a half times its original (本来的) value. The mistake was made more than a hundred years ago in the British colony (殖民地)of Mauritius, a small island in the Indian Ocean. In 1847 an order for stamps was sent to a London printer—Mauritius was to become the fourth country in the world to issue (发行) stamps.
Before the order was delivered(传达), a party was planned at Mauritius’Government House, and stamps were needed to send out the invitations. A local printer was told to copy the design for the stamps. He printed the words " Post Office " instead of " Post Paid " by mistake on the several hundred stamps that he printed.
Today there are only twenty-six of these misprinted stamps left—fourteen Onepenny Orangereds and twelve Twopenny Blues. Because of the Twopenny Blue’s rareness (稀少) and age, collectors have paid as much as $ 16800 for it.

The best title for this selection is ______.

A．The "Post Office" Mistake

B．The Twopenny Blue

C．A London Printer’s Mistake

D．How Maurius Became Famous

如图所示为采集亚运圣火的画面，22岁的云南姑娘康辰晨借助一个凹面反射镜采集太阳光点燃火炬。火炬中的燃气是通过            方式使温度升高，内能增大而被点燃的。

如果一个满足1NF关系的所有属性合起来组成一个关键字，则在函数依赖的范围内，该关系最高满足的范式必然是

A．1NF

B．2NF

C．3NF

D．4NF

根据《工程建设施工企业质量管理规范》，施工企业应对项目经理部的质量管理活动进行监督检查，内容包括：项目质量管理策划结果的实施、对企业、发包方或监理方提出的意见和整改要求的落实、（）和质量目标的实现。

A.合同的履行情况

B.质量文件的落实情况

C.质量人员资格审查情况

D.质量管理制度的实施情况

简述矿物共生组合及其确定标志。