燃烧炉的温度表有何作用？

公司债券具有特征。

A.收益率较高

B.优先索取权

C.风险性较大

D.绝对的选择权

E.相对的选择权

从以下12个词中选择最恰当的8个，分别填入答题卡相应的位置上。选词不得重复。

探讨　举行　格局　走过　见证　关心

坦率　开拓　开创　形式　举办　关注

　　中日经济讨论会始于1984年，基本上每两年　①　一次，分别在中国和日本交替召开，从第一次　②　“中国对外开放政策和中日经济合作”，到今天已经　③　了26个年头，它不仅　④　了中国的改革开放和经济发展，也见证了世界经济的　⑤　变迁。第13次中日经济讨论会于9 月3日在长春举行。在世界经济进入“后金融危机时代”的大背景下，“推动世界经济增长的引擎——中日合作的机遇与课题”这一会议主题引起了中日两国政府、媒体、企业界和学术界人士的极大　⑥　。300多位中日两国与会者　⑦　地谈论了中日两国经济现状，并就如何在当前形势下　⑧　新的中日经济合作领域提出各种设想和建议。

答：____________________________________________________________

与细菌抵抗吞噬有关的是（）。

A.荚膜

B.芽胞

C.鞭毛

D.菌毛

E.异染颗粒

估测二尖瓣瓣口面积最常用、最可靠的方法为（）

A.二维测量瓣口面积法

B.跨瓣压差测量法

C.频谱多普勒连续方程法

D.近端等速表面积法（PISA.

E.二尖瓣口压力减半时间法

In looking at the class structure of an entire system, we may find that its inheritance (1) is either wide and shallow, narrow and deep, or balanced. Class structures that are wide and shallow usually represent forests of (2) classes that can be mixed and matched. Class structures that are narrow and deep represent trees of classes that are related by a common ancestor. There are advantages and disadvantages to each approach. Forests of classes are more loosely (3) , but they may not exploit all the commonality that exists. Trees of classes exploit this commonality, so that individual classes are smaller than in forests. However, to understand a particular class, it is usually necessary to understand the meaning of all the classes it inherits from or uses. The proper shape of a class structure is highly problem-dependent.
We must make similar trade-offs among inheritance, aggregation, and using relation- ships. For example, should the class Car inherit, contain, or use the classes named Engine and Wheel In this case, we suggest that an (4) relationship is more appropriate than inheritance relationship. Meyer states that between the class A and B," (5) is appropriate if every instance of B may also be viewed as an instance of A. The client relationship is appropriate when every instance of B simply possesses one or more attributes of A". From another perspective, if the behavior of an object is more than the sum of its individual parts, then creating an aggregation relationship rather than an inheritance relationship between the appropriate classes is probably superior.

(5)

A．aggregation

B．inheritance

C．association

D．using