搜题请搜索小程序“爱下问搜题”
问题 多项选择题

防止靠近煤壁附近的局部冒顶的措施是（）。

A、采用能及时支护悬露顶板的支架

B、在架设支架前敲帮问顶

C、炮采时，炮眼布置及装药量应合理，尽可能避免崩倒支柱

D、支架必须有足够的支撑力

E、支护系统必须始终没有发生局部冒落的“空档

答案

参考答案：A, B, C

填空题


In the following passage, there are 25 blanks representing words that are missing from the context. You are to put back in each of the blanks the missing word. Write your answers on the ANSWER SHEET. The time for this section is 25 minutes.
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.

查看答案
单项选择题

既然总速度是环比发展速度的连乘积，那么平均发展速度就应按（）

A.简单算术平均数计算

B.加权算术平均数计算

C.几何平均数计算

D.调和平均数计算
查看答案