如果一个矩形的长和宽是一元二次方程x2﹣10x+20=0的两个根，那么这个矩形的

下列化学变化中，需加入氧化剂才能实现的是（　　）

A．C→CO₂

B．CO₂→CO

C．CuO→Cu

D．H₂SO₄→BaSO₄

金属板安装应符合的规定包括（）

A.应对横竖连接件进行检查、测量、调整

B.金属板安装时，左右、上下的偏差不应大于3mm

C.金属板空缝安装时，必须有防水措施，并应有符合设计要求的排水出口

D.填充硅酮耐候密封胶时，金属板缝的宽度、厚度应根据硅酮耐候密封胶的技术参数，经计算后确定

E.幕墙钢构件施焊后，其表面应采取有效的防腐措施

把预付资本划分为不变资本和可变资本的依据是

A．资本的不同部分价值周转的不同方式

B．预付资本的不同部分在资本价值增殖中的不同作用

C．资本投入的不同部门的资本有机构成

D．资本投入的不同领域资本周转的不同速度

下列关于个人贷款还款方式的表述中，正确的是（）。

A.等额累进还款法与等比累进还款法的相似之处在于，在每个时间段上约定还款的固定额度

B.等额累进还款法与等比累进还款法的相似之处在于，当借款人还款能力发生变化时，只能通过调整累进额来适应客户还款能力的变化

C.对收入减少的客户，可采取增大累进额、缩短间隔期等办法，使借款人分期还款额增多，从而减少借款人的利息负担

D.等额累进还款法中，对收入水平下降的客户，可采取减少累进额、扩大累进间隔期等办法使借款人分期还款额减少，以减轻借款人的还款能力

Attempts to understand the relationship between social behavior and health have their origin in history. Dubos (1969) suggested that primitive humans were closer to the animals (1) they, too, relied’upon their instincts to stay healthy. Yet some primitive humans (2) a cause and effect relationship between doing certain things and alleviating (3) of a disease or (4) the condition of a wound. (5) there was so much that primitive humans did not (6) the functioning of the body, magic became an integral component ofthe beliefs about the causes and cures of heath (7) Therefore it is not (8) that early humans thought that illness was caused (9) evil spirit. Primitive medicines made from vegetables or animals were invariably used in combination with some form of ritual to (10) harmful spirit from a diseased body.

One of the. earliest (11) in the Western world to formulate principles of health care based upon rational thought and (12) of supernatural phenomena is found in the work of the Greek physician Hippocrates. The writing (13) to him has provided a number of principles underiying modern medical practice. One of his most famous (14) , the Hippocratic Oath, is the foundation of contemporary medical ethics.

Hippocrates also argued that medical knowledge should be derived from a (15) of the natural science and the logic of cause and effect relationships. In this (16) thesis, On Air, Water, and Places, Hippocrates pointed out that human well-being is (17) by the totality of environmental (18) : living habits or lifestyle, climate, geography of the land, and the quality of air, and food. (19) enough, concerns about our health and the quality of air, water, and places are (20) very much written in twentieth century.

18（）

A.elements

B.factors

C.components

D.deposits