Hayem红细胞稀释液中硫酸钠的主要作用是（）A．固定细胞形态 B．防腐作用 C．防

在充分竞争条件下，运输能力富裕的运输方式需求价格弹性表现为（）。

A.完全无弹性

B.单位弹性

C.富有弹性

D.缺乏弹性

便秘由下列（）

A.氨的毒性增加

B.氨的生成增加

C.氨的吸收增加

D.组织对氨的敏感性增加

E.促进氨透过血脑屏障

装修材料按其燃烧性能分为几级（）

A、一级

B、二级

C、三级

D、四级

The basic flag of the United States is one of the world’s oldest national flags. Only the basic flags of Austria, Denmark, Great Britain, the Netherlands, Sweden, and Switzer land are older.

During the discovery and settlement of what is now the United States, the flags of various European nations were flown over the land, as symbols of possession. Later, in the Colonial and Revolutionary War periods, flags representing famous persons, places, and events were flown in the American Colonise.

The first official flag of the United States was created by Congress on June 14, 1777. It consisted of 13 alternate red and white stripes and 13 white stars in a field of blue, representing the 13 colonies that had declared their independence in 1776. Congress adopted a new flag of 15 stars and 15 stripes in 1795, to give representation to the two new states admitted into the Union, Vermont and Kentucky.

By 1817, there were 20 states in the Union, and it became apparent that adding one stripe for each new state would destroy the shape of the flag. As a result, Congress in 1818 restored the original design of 13 stripes and provided that each state was to be represented by one star. In 1921 Preside William H. Taft made the first official provision for the arrangement of the stars. He ordered that there be six even rows of eight stars each. Previously the arrangement of the stars had been left to the flag- maker’s fancy.

The evolution of the stars and stripes reflects the growth of the United States. After the admission of Hawaii into the Union in 1959, the flag was official changed for the 26th time since its creation.

There are many government flags flown in the United States in addition to the national flag. Among them are the president’s and vice- president’s flags and those of the federal departments and some federal agencies. Each state in the Union has an official flag. The United States Navy uses special flags for signaling.

小题1: The basic flag of the United States is _______.

A．the oldest national flag in the world

B．one of the world’ s oldest flags

C．the most beautiful flag in the West

D．as old as the basic flags of some European nations小题2: Before the War of Independence the flags of various European nations flown over the land were symbols of _______.

A．self- rule

B．occupation

C．peace and friendship

D．independence小题3: The first official flag of the United States was adopted ________.

A．before the Independence War

B．right after the Independence War

C．when independence was declared in 1776

D．during the War of Independence which ended in 1783小题4:The 13 red and white stripes and 13 white stars represent _______.

A．13 independent states

B．the colonies that declared independence in 1776.

C．the U. S. Congress

D．13 famous figures in the American colonies小题5:How many states were represented on the new flag adopted in 1795?

A．13.

B．15.

C．20.

D．2.

按子项目组成编制的施工成本计划，首先要把项目总施工成本分解到（）和单位工程中去。

A．分部工程

B．分项工程

C．检验批

D．单项工程