题干

设函数f(x)=
x
x
+
1
(x>0),记f1(x)=f(x),f2(x)=f(f1(x)),fn+1(x)=f[fn(x)].则f2017(x)等于(   )

A:x2017x+1

B:xx+2017

C:2017x2017x+1

D:2017x+1x

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答案(点此获取答案解析)

A

同类题1

阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

    Answers to life can be found in everyday events. Watching nature, watching people and watching animals communicate with each other provide some of the simplest ways to life's biggest problems.

    This became clearer to me yesterday. It caused me to ask myself, “How do I respond (反应) to the storms in life?”

    People usually run when it starts to rain. I love to walk in it, stand on my front door and feel it. I grew up doing it and have never really felt the fear many people do.

    The animal world senses changes in the weather far earlier than humans. My dog, Ricky, begins to shake long before the storm is close enough to be noticed. I was about to feed my three dogs yesterday and as usual, I let them out in the yard first. They didn't move when thunder came across the skies. So I placed their food in their bowls and called Ricky into the kitchen.

    Ricky was just standing there in place next to his bowl. The thunder became louder, which forced him to stop eating his meal. Then I watched Phil. He made his way across the kitchen floor and stood over Ricky's bowl. He ate all the remaining food. Generally, if Ricky was standing there, he wouldn't dare (敢) come close. But today, he took advantage (优势) of the storm and got what he wanted. His hope for the prize outweighed (胜过) his fear of the storm.

    That's when it hit me. As men, we face all kinds of storms. They come in unannounced. Sometimes we stay in a corner or under the blankets, hoping it will all pass. However, if you dare put your head out, you'll discover there're people doing what they must to get what they must have out of life. Isn't it time you decided to take advantage of the storm?

同类题5

阅读下文,回答问题。

爸爸的花儿落了

      当当当,钟声响了,毕业典礼就要开始。看外面的天,有点阴,我忽然想,爸爸会不会忽然从床上起来,给我送来花夹袄?我又想,爸爸的病几时才能好?妈妈今早的眼睛为什么红肿着?院里大盆的石榴和夹竹桃今年爸爸都没有给上麻渣②,他为了叔叔给日本人害死的事,急得吐血了,到了五月节,石榴花开得没有那么红,那么大。如果秋天来了,爸爸还要买那样多的菊花,摆满在我们的院子里、廊檐下、客厅的花架上吗?

爸爸是多么喜欢花。

      每天他下班回来,我们在门口等他,他把草帽推到头后面,抱起弟弟,经过自来水龙头,拿起灌满了水的喷水壶,唱着歌儿走到后院来。他回家来的第一件事就是浇花。那时太阳快要下去了,院子里吹着凉爽的风,爸爸摘一朵茉莉插到瘦鸡妹妹的头发上。陈家的伯伯对爸爸说:“老林,你这样喜欢花,所以你太太生了一堆女儿!”我有四个妹妹,只有两个弟弟。我才12岁……

      我为什么总想到这些呢?韩主任已经上台了。他很正经地说:“各位同学都毕业了,就要离开上了六年的小学到中学去读书,做了中学生就不是小孩子了,当你们回到小学来看老师的时候,我一定高兴地看到你们都长高了,长大了……”

      于是我唱了五年的骊歌,现在轮到同学们唱给我们送别:“长亭外,古道边,芳草碧连天。问君此去几时来,来时莫徘徊!天之涯,地之角,知交半零落,人生难得是欢聚,惟有别离多……”

      我哭了,我们毕业生都哭了。我们是多么喜欢长高了变成大人,我们又是多么怕呢!当我们回到小学来的时候,无论长得多么高,多么大,老师!你们要永远拿我当个孩子呀!

      做大人,常常有人要我做大人。

      ……

      快回家去!快回家去!拿着刚发下来的小学毕业文凭——红丝带子系着的白纸筒,催着自己,我好像怕赶不上什么事情似的,为什么呀?

      进了家门来,静悄悄的,四个妹妹和两个弟弟都坐在院子里的小板凳上,他们在玩沙土,旁边的夹竹桃不知什么时候垂下了好几个枝子,散散落落地很不像样,是因为爸爸今年没有收拾它们——修剪、捆扎和施肥。

      石榴树大盆底下也有几粒没有长成的小石榴,我很生气,问妹妹们:“是谁把爸爸的石榴摘下来的?我要告诉爸爸去!”

      妹妹们惊奇地睁大了眼,她们摇摇头说:“是它们自己掉下来的。”

      我捡起小青石榴。缺了一根手指头的厨子老高从外面进来了,他说:“大小姐,别说什么告诉你爸爸了,你妈妈刚从医院来了电话,叫你赶快去,你爸爸已经……”他为什么不说下去了?我忽然觉得着急起来,大声喊着说:“你说什么?老高。”

      大小姐,到了医院,好好儿劝劝你妈,这里就数你大了!就数你大了!”

      瘦鸡妹妹还在抢燕燕的小玩意儿,弟弟把沙土灌进玻璃瓶里。是的,这里就数我大了,我是小小的大人。我对老高说:“老高,我知道是什么事了,我就去医院。”我从来没有过这样的镇定,这样的安静。

      我把小学毕业文凭,放到书桌的抽屉里,再出来,老高已经替我雇好了到医院的车子。走过院子,看到那垂落的夹竹桃,我默念着:爸爸的花儿落了,我也不再是小孩子。