问题 选择题

始祖鸟烯(Pterodactyladiene)形状宛如一只展翅飞翔的鸟,其键线式结构表示如下,其中R1、R2为烷烃基。则下列有关始祖鸟烯的说法中正确的是

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A.始祖鸟烯与乙烯互为同系物

B.若R1=R2=甲基,则其化学式为C12H16

C.若R1=R2=甲基,则始祖鸟烯的一氯代物有3种

D.始祖鸟烯既能使酸性高锰酸钾溶液褪色,也能使溴水褪色,则两反应的反应类型是相同的

答案

答案:C

单项选择题

Why is()fun What delights may its practitioner expect as his reward First is the sheer joy of making things. As the child delights in his mud pie, so the adult enjoys building things, especially things of his own design. Second is the pleasure of making things that are useful to other people. Third is the fascination of fashioning complex puzzle-like objects of interlocking moving parts and watching them work in subtle cycles, playing out the consequences of principles built in from the beginning. Fourth is the joy of always learning, which springs from the()nature of the task. In one way or another the problem is ever new, and its solver learns something: sometimes (), sometimes theoretical, and sometimes both. Finally, there is the delight of working in such a tractable medium. The(), like the poet, works only slightly removed from pure thought-stuff. Few media of creation are so flexible, so easy to polish and rework, so readily capable of realizing grand conceptual structures. Yet the program(), unlike the poet’s words, is real in the sense that it moves and works, producing visible outputs separate from the construct itself. It prints results, draws pictures, produces sounds, moves arms. Programming then is fun because it gratifies creative longings built deep within us and delights sensibilities we have in common with all men.

Why is()fun What delights may its practitioner expect as his reward First is the sheer joy of making things.

A.programming

B.composing

C.working

D.writing

单项选择题