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问题 选择题

鱼不停的吞水吐水，与吞入的水相比，吐出的水（　　）

A．二氧化碳增多

B．氧气增多

C．尿酸、尿素等物资减少

D．二氧化碳减少

答案

鱼生活在水中，用鳃呼吸，用鳍游泳，鳃是鱼类的重要呼吸器官，鱼体与外环境的气体交换主要由鳃来完成．鱼不停的吞水和吐水，主要是为了呼吸．吐出水与吸入水相比增多的气体是二氧化碳．其根本原因就是吸入的氧要提供组织细胞进行呼吸作用释放能量供生命活动需要，同时这个过程产生了大量的二氧化碳由鱼呼出，导致吐出的气体二氧化碳含量增加．

故选：A

填空题

Motivation is "the driving force within individuals that impels them to action." And goals are the sought-after results_____(1) motivated behavior.Motivation can be either positive or negative_____(2) direction. We may feel a driving force toward some object or condition, _____(3) a driving force away from some object or condition. For example, a person may be impelled toward a restaurant to fulfill a need, hunger, and away_____(4) an airplane to fulfill a need of safety. Some psychologists refer to positive drives_____(5) needs, wants or desires,_____(6) negative drives as fears or aversions._____ (7), though negative and positive motivational forces seem to differ dramatically_____(8) terms of physical and sometimes emotional activity, they are basically similar in_____(9) they both serve to initiate and sustain human behavior.____(10) this reason, researchers often refer _____(11) both kinds of drives or motives as needs, wants and desires.Goals, _____(12), can be either positive or negative. A positive goal is one toward_____ (13) behavior is directed and it is often referred to as an approach object. A negative goal is _____(14) from which behavior is directed away and it is sometimes referred to as an avoidance object. Since both approach and avoidance goals can be considered objectives of motivated behavior, most researchers refer to_____(15) types simply as goals. Consider this example. A middle-aged woman may wish to remain_____(16) attractive as possible. Her positive goal is to appear desirable, and_____(17) she may use a perfume advertised to make her irresistible. A negative goal may be to prevent her skin_____(18) aging, and therefore she may buy and use face creams._____(19) the former case, she uses perfume to help her achieve her positive goal — attractiveness; in the____(20) case, she uses face creams to help avoid a negative goal — wrinkled skin.
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填空题

（6分）某同学在四个烧杯中分别做有关溶液实验，依据表格回答问题。

烧杯序号温度/℃水的质量/g硝酸钾质量/g溶液质量/g
①20501060
②2010030a
③2010036131.6
④3010045145
（1）硝酸钾溶液中的溶剂是__________。

（2）20℃时硝酸钾的溶解度是         g，a为      。

（3）将烧杯①所得溶液稀释成溶质的质量分数为10%的溶液，需要加水       g。

（4）若使烧杯③溶液中溶质的质量分数增大，可继续__________（填字母序号）。

A.加入少量硝酸钾

B.再加10g水

C.恒温蒸发部分溶剂

D.升温到30℃

E. 加入100 g 30℃时硝酸钾的饱和溶液，再恢复至20℃

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