用户在组合框中输入或选择的数据可以通过( )属性来获得。A．List B．List

肺炎双球菌的转化实验中，发生转化的细菌和含转化因子的细菌分别是[ ]

A．R型细菌和S型细菌

B．R型细菌和R型细菌

C．S型细菌和S型细菌

D．S型细菌和R型细菌

六、阅读下面文字，完成下面4个小题。

　　美国科学家声称，每人生来有两个脑，即颅脑与肠脑。

　　肠脑位于食管、胃脏、小肠与结肠内层组织的鞘中，含有神经细胞、神经传递质、蛋白质和复杂的环行线路。结肠炎、过敏性肠综合症等都与肠脑内产生的问题有关。肠脑中几乎能找到颅脑赖以运转和控制的所有物质，如血清素、多巴胺、谷氨酸、去甲肾上腺素、一氧化氮等。此外，肠脑中还存在多种被称为神经肽的脑蛋白、脑啡肽以及对神经起显著作用的化学物质。

　　颅脑面临惊恐时释放的应激激素会冲击胃脏发生痉挛；惊恐又引起交感神经影响肠脑的血清素分泌量。应激激素的过分刺激还会导致腹泻。当情绪压抑时，食管神经受到高度刺激会感到吞咽困难；颅脑释出的应激激素还会改变胃脏与食管间的神经功能，导致胃灼热。

　　最初的脑神经系统起始于管形动物，生存竞争需要更复杂的颅脑，从而发展了中枢神经系统。重要的肠神经系统不能进入头颅与胃肠相联，而为了适应高级动物进食和消化的需要，自然法则就保存了有独立功能的肠神经系统。就人而言，早期胚胎发育中产生的神经脊，一部分进入了中枢神经系统，另一部分变成肠神经系统，通过迷走神经连接两者――颅脑和肠脑。

根据文意，肠脑之所以称为“脑”，下列理解不准确的一项是（）。

A．它是不依赖中枢神经系统而独立活动的神经系统

B．它的物质构成含有神经细胞及对其起显著作用的物质

C．它具有同颅脑一样的能够控制肠胃运转的独立功能

D．它起源于管形动物的脑神经系统并从中分化出来

根据合同法的规定，下列哪些技术合同无效？

A．甲公司与乙公司签订的技术开发合同，约定就开发完成的发明创造申请专利的权利属于甲公司

B．丙公司与丁公司签订的技术服务合同，约定丁公司不得从其他公司获得类似技术或者其他竞争性技术

C．戊公司与己公司签订的技术转让合同，约定己公司购买与实施该技术无关的大型设备5台

D．庚公司与辛公司签订的专利实施许可合同，约定辛公司不得对该专利提出无效宣告请求

阅读理解

     Friends play an important part in our lives, and although we may take the fact of friendship for

granted, we often don't clearly understand how we make friends. While we get on well with a number

of people,     1   .

     Moreover, a great many relationships come under the general term “friendship”. In all cases, two

people like one another and enjoy being together, but beyond that, the degree of closeness between

them and the reasons for their interest in each other change greatly.

     At the beginning, much depends on how people meet, and on good first impressions. As we get to

know people,   2    . Although these factors are not of the greatest importance, it is more difficult to have

a good relationship with people when there is a big difference in age and background.

     Then,     3   . Friends will stand closer together and will spend more time looking at each other than

ordinary friends. Smiles and soft voices also express friendliness, and it is because they may give the

wrong signals that shy people often have difficulty making friends. A friendly look with a wrong facial

expression can turn into an unfriendly stare, and nervousness may be wrongly understood as unfriendliness.

     Some relationships are a result of argument and discussion, but it is usual for close friends to have the

same ideas and beliefs, the same opinions and interests. The more closely involved people become, the

more they depend on each other. And    4    . Equally, friends have to learn to make allowances for each

other, to put up with annoying habits, and to accept differences in opinions.

     In contrast with marriage,     5    . But the support and understanding that results from shared

experiences and affections does seem to create a close and lasting relationship.

A. we are usually friends with only a few

B. many factors can affect friendship and relationship

C. people want to do friends favors and hate to let them down

D. argument and discussion can improve personal relationships

E. we consider things like age, race, looks, economic and social status, etc.

F. we pay attention to actual behavior, facial expression, and the way a person speaks

G. there are no friendship ceremonies to strengthen the relationship between two people

驾驶人行车中看到注意儿童标志的时候，应怎样做？

A．加速行驶

B．绕道行驶

C．谨慎选择行车速度

D．保持正常车速行驶