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问题 选择题

通常光学显微镜下不易观察到植物细胞的（　　）

A．细胞核

B．细胞质

C．细胞膜

D．细胞壁

答案

不同的结构据有不同的特点．

A、细胞核内含有遗传物质，能够传递遗传信息，个体较大，在显微镜下很容易找到，故不符合题意．

B、细胞质位于细胞核的外面和细胞膜的里面，具有流动性，在显微镜下容易找到，故不符合题意．

C、细胞膜是紧贴在细胞壁上的一层透明且极薄的膜，具有控制进出的作用，使有用的物质不能任意的渗出细胞，有害的物质不能轻易地进入细胞．在显微镜下不易观察到，故符合题意．

D、细胞壁位于细胞的最外面，具有保护、支持细胞的功能，在显微镜下很容易找到，故不符合题意．

故选：C

单项选择题

下列说法错误的是（）。

A．操作系统管理计算机的硬件，所以随着硬件的不断更新，操作系统也需要更新换代

B．应用软件在操作系统的基础上运行，通过操作系统实现对硬件的操作

C．用户可以直接对硬件进行操作

D．用户操作的是计算机通过操作系统展现在用户眼前的逻辑设备
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填空题

Some consumer researchers distinguish (1) "rational" motives and "emotional" (or "non-rational") motives. They use the term "rationality" (2) the traditional economic sense that assumes (3) consumers behave rationally when they carefully consider all alternatives (4) choose those that give them the greatest utility (i.e., satisfaction). (5) a marketing context, the term "rationality" implies that the consumer selects goods based (6) totally objective criteria, such (7) size, weight, price, and so on. "Emotional" motives imply the selection of goods (8) to personal or subjective criteria—the desire (9) individuality, pride, fear, affection or status.
The assumption underlying this distinction is (10) subjective or emotional criteria do not maximize utility or satisfaction. (11) , it is reasonable to assume that consumers always attempt to select alternatives that, (12) their view, serve to maximize satisfaction. Obviously, the assessment of satisfaction is a very personal process, based (13) the individual’s own needs as (14) as on past behavioral, social, and learning experiences. What may appear (15) irrational to an outside observer may be perfectly rational (16) the context of the consumer’s own psychological field. For example, a product purchased to enhance one’s self-image (such as a fragrance) is a perfectly rational form of consumer behavior. (17) behavior did not appear rational to the person who undertakes it (18) the time that it is undertaken, obviously he or she would not do it. (19) the distinction between rational and emotional motives does not appear to be warranted.
Some researchers go so far (20) to suggest that emphasis (21) "needs" obscures the rational, or conscious, nature of most consumer motivation. They claim that consumers act consciously (22) maximize their gains and minimize their losses; that they act not (23) subconscious drives but from rational preferences, (24) what they perceive to be (25) their own best interests.
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