2010年是太阳能热水器产业发展年、起飞年,有人评价它是,“身披再生能源大衣,高

题型:计算题

问题:

2010年是太阳能热水器产业发展年、起飞年,有人评价它是,“身披再生能源大衣,高举低碳生活大旗”.小周同学家有一台太阳能热水器,水箱容积是200L.小周进行了一次观察活动:某天早上,他用温度计测得自来水的温度为20℃,然后给热水器水箱送满水,中午时45℃,请你求解下列问题: 

(1)求水箱中水的质量和水吸收的热量.[=4.2× J/(kg.℃)]  

(2)如果水吸收的这些热量,由燃烧煤气来提供,而煤气灶的效率为40%,求至少需要燃烧多少煤气?(煤气的热值为q =4.2×J/kg)

考点:热量的计算热值能量转化效率密度公式的应用
题型:计算题

It was ______ the second-hand bus that the mechanic spent the whole afternoon in the factor.

[ ]

A. in repair

B. repaired

C. repairing

D. to repair

题型:计算题

最可能的诊断

A.滴虫性 * * 炎

B.念珠菌性 * * 炎

C.细菌性 * * 病

D.淋菌性 * * 炎

E.支原体性 * * 炎

题型:计算题

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.

题型:计算题

正常人不易引起口腔感染,是由于唾液中有()

A.淀粉酶

B.氨基酸

C.尿素

D.溶菌酶

E.粘蛋白

题型:计算题

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