采用标幺制计算时,只需要选择两个电气量的基准值,其它电气量的基准值可以根据它们之间的

题型:单项选择题

问题:

采用标幺制计算时,只需要选择两个电气量的基准值,其它电气量的基准值可以根据它们之间的关系导出,通常的选择方法是()

A、选择功率和电压基准值

B、选择功率和电流基准值

C、选择功率和阻抗基准值

D、选择电压和阻抗基准值

考点:电力系统调度运行考试电力系统调度运行考试题库
题型:单项选择题

关于慢性心功能不全的代偿机制中,下列哪项不正确()

A.交感神经兴奋

B.水钠潴留

C.心肌肥厚

D.迷走神经兴奋

E.心房钠尿肽释放

题型:单项选择题

常用的组织结构模式包括职能组织结构、()和矩阵组织结构。

A.环形组织结构

B.线性组织结构

C.菱形组织结构

D.方形组织结构

题型:单项选择题


The United States counts its population every ten years, and each census reveals that the racial and ethnic mix is changing dramatically, so by the year 2050, the "average" American will not be descended from (1) , but the majority of U. S. residents will trace (2) ancestry to Africa, Asia, the Hispanic world, the Pacific Islands, or the Middle East. Once the United States was a microcosm of European nationalities, (3) the United States is a microcosm of the world. The United States is (4) considered a "melting pot" society by many of its residents. (5) , many people prefer the term "salad bowl." They use this (6) to describe American society. American society will soon be (7) nonwhite. "Melting pot" implies that the different ethnic groups blend together (8) one homogeneous (9) , "salad bowl" (10) that nationalities, like the ingredients in a mixed green salad, retain their cultural (11) . Earlier generations of (12) believed they had to learn English quickly not only to survive but also for (13) .
Now, many immigrant groups do not (14) the same need. Because there are many places in America (15) you can work, shop, get medical care, marry, divorce and die without knowing English. (16) , Chinatown in San Francisco and New York. Also, Los Angeles has many Vietnamese immigrants and immigrants from Mexico. (17) , many immigrant groups want their children to know their (18) culture. Many Hispanics, for instance, want their children to learn (19) English and Spanish and study the Spanish language in school. They are fighting for the (20) to bilingual education in many communities. In many communities they are in the majority.

题型:单项选择题

流行性脑脊髓膜炎败血症期患者皮肤淤点的主要病理基础是()。

A.血管脆性增强

B.弥散性血管内凝血

C.血小板减少

D.小血管炎致局部坏死及栓塞

E.凝血功能障碍

题型:单项选择题

CDMA系统中主要存在的是哪种干扰?

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