问题 选择题

下列可构成原电池的是

答案

答案:B

题目分析:原电池的构成条件是:①有两个活泼性不同的电极,②将电极插入电解质溶液中,③两电极间构成闭合回路,④能自发的进行氧化还原反应。原电池中正极上发生还原反应,负极上发生氧化反应。A中电极相同,C中酒精是非电解质,D中没有形成闭合回路,均不能形成原电池。B中铁是负极,Sn是正极,构成原电池,所以正确的答案选B。

点评:该题是高考中的常见考点,属于基础性试题的考查,难度不大。明确原电池的工作原理、构成条件是答题的关键。有利于培养学生的逻辑推理能力和发散思维能力,提升学生的学科素养。

填空题
阅读理解

The fact that blind people can see things using other parts of their bodies apart from their eyes may help us to understand our feelings about color. If they can sense color differences, then perhaps we, too, are affected by color without knowing it. Salesmen have discovered by experience over a long period of time that sugar sells badly in green wrappings, that blue foods are considered not agreeable to the taste ,and that cosmetics (化妆品) should never be packed in brown. These discoveries have grown into a whole subject of color psychology (心理学).

Some of our preferences(偏爱)are clearly psychological. Dark blue is the color of the night sky and therefore connected with calm, while yellow is a day color connected with energy and encouragement. Experiments have shown that colors, partly because they are connected with psychology, also have a direct effect on people’s mind. People in bright red surroundings show an increase in breathing speed, heartbeat and blood pressure. Red is exciting. Pure blue has exactly the opposite effect; it is a calming color. Being exciting, red was chosen as the signal for danger, but a closer study shows that a bright yellow can produce a more basic state of alarm, so fire engines in some advanced areas are now rushing around in bright yellow colors that stop buses, trucks and cars.

53. The passage tells us that salesmen have _______.

A. found out that colors affect sales

B.discovered the relationship between color and psychology

C. tried colors on blind people

D. developed a special subject of color psychology

54. If people are exposed to (置身于) pure blue, _______.

A. their body pressure rises          B.they won’t easily feel nervous

C. they want to taste blue foods      D. they will feel like buying things

55. The most effective color in the passage for warning people is _____.

A. red     B.bright yellow     C. dark blue     D. green

56. Which of the following do you think is the best title of the passage?

A. Color and Feelings               B.Colors and Sales

C. The Blind and Colors              D. Preferences for Colors