绝缘栅双极晶体管指的是()。 A.MOSFET B.GT0 C.IGBT D.GTR

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问题:

绝缘栅双极晶体管指的是()。

A.MOSFET

B.GT0

C.IGBT

D.GTR

考点:维修电工考试维修电工(技师)维修电工(技师)题库
题型:单项选择题

速动比率指标是用于反映项目( )。

A.偿债能力

B.偿付流动负债的能力

C.财务风险程度

D.快速偿付流动负债能力

题型:单项选择题

有机物A是重要的化工合成原料,在医药、染料和香料等行业有着广泛的应用.由A制得某药物H的转化关系如图所示(A→G、G→H的反应条件和部分反应物已略去).

请回答下列问题:

(1)已知有机物A的相对分子质量为106,且A中所含碳、氢、氧三种元素的质量之比为42:3:8,则A的结构简式为______,检验A中含氧官能团的方法是______.

(2)下列关于药物H的说法正确的是______(填序号).

A.H的分子式为C10H15NO

B.该物质的核磁共振氢谱图中有9组峰

C.H属于芳香烃

D.H能发生加成反应、消去反应、氧化反应

(3)写出D→B的化学方程式:______.

(4)反应①~⑤中属于取代反应的是______(填序号).

(5)B和C反应生成F的化学方程式为______.

(6)写出符合下列条件的G的同分异构体的结构简式:______.

①既能发生消去反应,又能发生酯化反应;

②苯环上的一氯取代物只有两种,分子结构中没有甲基;

③能发生银镜反应.

题型:单项选择题

某饭店有客房200间,公布房价为200元。某日销售客房100间,房费收入为16000元。请回答下列问题:

该饭店当日的客房收益率是()%。

A.100

B.80

C.60

D.50

E.40

题型:单项选择题

生物利用度是指()。测定方法常有()、()两种。

题型:单项选择题

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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