问题 选择题

下列对于合金性质的叙述不正确的是(   )

A.合金的熔点低于它的任何一种成分金属的熔点

B.合金的硬度一般比各成分金属的硬度都大

C.合金的密度小于各成分金属的密度

D.合金的导电性、导热性比各成分金属低

答案

答案:C

合金有如下三个特征:熔沸点一般比任一组分低,硬度比任一组分大,密度介于两者之间。故不正确的叙述为C选项。

选择题
单项选择题

The history of responses to the work of the artist Sandro Botticelli (1444 ~ 1510) suggests that widespread appreciation by critics is a relatively recent phenomenon. Writing in 1550, Vasari expressed an unease with Botticelli’s work, admitting that the artist fitted awkwardly into his evolutionary scheme of the history of art. Over the next two centuries, academic art historians defamed Botticelli in favor of his fellows Florentine, Michelangelo. Even when anti-academic art historians of the early nineteenth century rejected many of the standards of evaluation adopted by their predecessors, Botticelli’s work remained outside of accepted taste, pleasing neither amateur observers nor connoisseurs. (Many of his best paintings, however, remained hidden away in obscure churches and private homes. )

The primary reason for Botticelli’s unpopularity is not difficult to understand: most observers, up until the midnineteenth century, did not consider him to be noteworthy, because his work, for the most part, did not seem to these observers to exhibit the traditional characteristics of fifteenth-century Florentine art. For example, Botticelli rarely employed the technique of strict perspective and, unlike Michelangelo, never used chiaroscuro.

Another reason for Botticelli’s unpopularity may have been that his attitude toward the style of classical art was very different from that of his contemporaries. Although he was thoroughly exposed to classical art, he showed little interest in borrowing from the classical style. Indeed, it is paradoxical that a painter of large-scale classical subjects adopted a style that was only slightly similar to that of classical art.

In any case, when viewers began to examine more closely the relationship of Botticelli’s work to the tradition of fifteenth-century Florentine art, his ’reputation began to grow. Analyses and assessments of Botticelli made between 1850 and 1870 by the artists of the Pre Raphaelite movement, as well as by the writer Pater (although he, unfortunately, based his assessment on an incorrect analysis of Botticelli’s personality), inspired a new appreciation of Botticelli throughout the English-speaking world. Yet Botticelli’s work, especially the Sistine frescoes, did not generate worldwide attention until it was finally subjected to a comprehensive and scrupulous analysis by Home in 1908. Home rightly demonstrated that the frescoes shared important features with paintings by other fifteenth-century Florentines features such as skillful representation of anatomical proportions, and of the human figure in motion. However, Home argued that Botticelli did not treat these qualities as ends in themselves--rather, that he emphasized clear depletion of a story, a unique achievement and one that made the traditional Florentine qualities less central. Because of Home’s emphasis crucial to any study of art, the twentieth century has come to appreciate Bottieelli’s achievements.

What does the author think of Botticelli’s representation skills()

A. They are to be fully appreciated

B. They evolve from an uncertain source

C. They underlie his personality

D. They conform to the classical style