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问题 选择题

下列现象中可以用光的直线传播规律解释的是（　　）

A．观赏水中的倒影

B．在树荫下躲太阳

C．用冰凸透镜取火

D．雨后天空出现彩虹

答案

A、水中的倒影是平面镜成像，是光的反射现象，不能用光的直线传播规律解释；

B、沿直线传播的太阳光遇到不透明的大树，阳光被挡住，照不到树下，在树下形成阴影，在树荫下躲太阳可以用光的直线传播规律解释；

C、光经过凸透镜后发生折射，会被汇聚在透镜的焦点上，用冰凸透镜取火是光的折射现象，不能用光的直线传播规律解释；

D、雨后天空出现彩虹是光的折射现象，不能用光的直线传播规律解释．

故选B．

多项选择题

水泥混凝土路面板横向缩缝的构造形式有（）。

A．原边型

B．假缝型

C．传力杆型

D．边缘钢筋型
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A Recent Erymology of the Word "Culture"“文化”一词的新词源
Look in an old dictionary—say, a pre-1960 Webster’s—and you’ll likely find a definition of culture (1) looks something like this: "1．The cultivation of soil. 2．The raising, improvement, or development of some plant, animal (2) product. " This use of the word has its roots in the ancient Latin word cultura, "cultivation" or "tending," and (3) entrance into the English language had begun by the year 1430. By the time the Webster’s definition above was (4) , another definition had begun to take precedence over the old Latin denotation; culture was coming to mean "the training, (5) , and refinement of mind, tastes, and manners" (Oxford English Dictionary). The OED traces this definition, which today we associate (6) the phrase "high culture," back as far as 1805; by the middle of the 20th century, it was (7) becoming the word’s primary definition.
However, if you try a more modem source, like the American Heritage English Dictionary, (8) find a primary definition of culture which is substantially different than either of the two given above: "The totality (9) socially transmitted behavior patterns, arts, beliefs, institutions, and all other products of human work and thought. " Why such a (10) , and in such a (relatively) short period of time Well, in the past 40 years, the use of the (11) "culture" has been heavily influenced by the academic fields of sociology and cultural anthropology. These fields have gradually brought (12) was once a minor definition of culture (the last of eight definitions given in the old 1958 Webster’s quoted (13) ) into the mainstream.
It is easy to imagine how the US society which was so focused on "socially transmitted (14) patterns" in the sixties would come to need a word to describe the object of its interest. The civil (15) movement during this era brought everyone’s attention to bear on cultural differences within US society, while the Vietnam War (16) to emphasize the position of the US culture in relation to other world cultures.
Over time, these new uses (17) the word culture have eclipsed its older meanings, those associated with cultivation of the land and the production of (18) . You might say that an aspect of US culture over the past 40 years is its fascination with the (19) of culture itself—a fascination which has brought about many changes in the way we speak and the (20) of words which we commonly use.

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