Why is (71) 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 hid 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 (72) nature of the task．In one Way or another the problem id ever new, and its solver learns something：sometimes (73) ，sometimes theoretical，and sometimes both．Finally there is the delight of Working in such a tractable medium．The (74) ，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 (75) ，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．

（75）处填（）。

A．construct

B．code

C．size

D．scale

智能手表的出现改变了我们对手表的概念，它不仅仅用来看时间，它可以与互联网相连，我们可能因此而改变生活习惯；同时我们还可以用它监测自己的健康状况，提高自己的健康水平。这反映出（）

①生产决定消费的方式

②消费是生产的最终目的

③消费为生产创造动力

④生产决定消费的质量与水平

A、①②

B、②③

C、③④

D、①④