题干

下面的三个图是某研究小组利用过氧化氢酶探究H2O2分解条件而获得的实验结果,有关叙述错误的是(    )

A:图一、二、三所代表的实验中,自变量依次为催化剂种类、H2O2浓度、pH

B:图一可以得出酶具有高效性

C:图二bc段产生的原因可能是过氧化氢酶数量(浓度)有限

D:图三可以得出pH越小或越大酶活性越高

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答案(点此获取答案解析)

D

同类题1

阅读《老赵的麦田》,完成下列小题。

老赵的麦田

刘立勤

    老赵的麦子终于黄了,眼前是金灿灿的一片。浓浓的麦香冲破重重的混凝土气息在老赵的胸腔肆意地冲撞,他的脸上是说不出的悲伤。

    为了这块麦田,老赵把人都得罪完了。

    城市是条贪吃的狼,要吃掉老赵的村子,老赵的麦田也被卖了。老赵不答应,他任凭村干部磨烂嘴皮子,也不愿让出自己的土地,而且不顾劝说地在地里种下了一茬麦子,他想用一地的麦子来阻挡拆迁的步伐。可那又有什么用呢?土地是集体的,村长还是带着挖机“轰隆隆”开往麦田。谁想老赵却不知死活地钻进挖机的轮下,愣是不让挖机进地。

    老板见多识广,以为老赵想讹钱,就拿来了大把大把的钱。那些钱够老赵盖三间大瓦房,也够买老赵种了一辈子的麦子呢。村里人眼红得不得了,都劝他见好就收。老赵还是不答应。有人不明白一向和善的老赵怎么会是这样,还有人骂他心重得像是吃了秤砣。老赵依然不管不顾,还是躺在轮子下面不出来。

    还是镇长出面,当了一辈子顺民的老赵才松了口,答应让出自己的土地。老赵也不要老板的青苗补偿,老赵的条件是等到夏天麦子黄了,他要收回自己那一季的麦子。

    老赵说,这也许是我这辈子能收获的最后一季麦子了。

    老赵是种庄稼的好手。只要有土,他就会撒下一把种子,或苞谷,或麦子,或黄豆,种下就是生机一片,让人眼气得恨不能挖了砍了拔了,却又让人喜欢得下不了手。就说老赵那一地的麦子吧,真是一地的好麦子呀,绿油油,齐壮壮,看一眼就会想到黄亮亮的麦粒、白胖胖的蒸馍、筋道道的捞面,让人忍不住咽口水。

    镇长讪讪地走了,村干部气愤愤地走了,老赵的亲戚来了。亲戚也舍不得那块麦子,可亲戚更关心老赵的日子。亲戚知道老赵是一根筋,亲戚就帮老赵算账。一笔一笔算,算到最后,亲戚说一根麦草都值两块钱了呢!老赵还是咬住那句话:我舍不得那一地的麦子。

    亲戚不高兴地走了,老赵在城里打工的儿子回来了。儿子不喜欢种地,初中毕业就去了南方打工,打了几年都是穷光蛋,混得远不如他这个种地的,臊得几年都不好意思回家。老赵不明白儿子为什么舍不得回家,不明白为什么还有那么多人往城里跑。

    儿子不喜欢种地,也不喜欢地里的麦子,可儿子喜欢地里麦子换来的钱。儿子逼着老赵让了土地好去领钱。儿子说,拿了钱可以在城里买房,可以在城里开店,可以买车,还可以给老赵娶一个儿媳妇生一个孙子。但任凭儿子说得天花乱坠,老赵就是不答应。儿子急了,就和他吵,和他闹,而且嚷嚷道要把地里的麦子割了去喂牛。儿子混,老赵不胜其烦,只好把攒的钱都给了儿子,把儿子赶进了城里。

    老赵好不容易保住了那一地的好麦子。他和老伴就在麦田的尽头搭了一个窝棚,守护着那一地的麦子。晴天里,老赵忙着给麦子拔草,杀虫,施肥;雨天了,就看麦子洗澡,喝水。四周的拆迁工程已经开始了,村里的人高兴地大呼小叫,麦田边的老赵呢,心里是一片宁静,安心等待着一田的麦子。

    麦子终于黄了,该割麦子了。镇长来了,村上的干部来了,老赵的邻居亲戚也来了,他们想看看老赵的麦田,想看老赵的麦田收割的是金子,还是银子。

    早先的挖机也来了,等着老赵收完了麦子,好在那块田里种上一座楼,或是一间厂房,或是一条街道。

    谁想到,老赵只割了三把麦子就离开了,挥手让挖机开进了麦田。挖机好像对麦田有仇一般,老赵的手还没有放下,就“轰隆隆”冲进了麦田。立马,麦田便是一片狼藉。片刻之间,麦田就没了。

同类题4

阅读理解

    I grew up in New Hampshire, a small town in South Canada, where in my father's words for the seasons were “Spring, Summer, Fairtime and Winter!”At that time, a week-long fair was held in the town every autumn. Thousands of people from other towns came to sell and buy things. It was the busiest time of the year.

    When “Fairtime” came, my grandma became the busiest person of the family. Grandma was a kind old lady. She was good at cooking. All her relatives liked the food she cooked. During “Fair time”, they would come to live in her house and have meals there. Grandma was always happy to look after them.

    Year after year, many people moved to big cities. There was no longer “Fairtime”. Grandma became very old and was gradually going blind. My parents and I moved to live with Grandma. We did our best to make her life comfortable. I was at high school then. What I often did at home was to help Grandma with the daily newspaper's crossword puzzle. However, she didn't look happy. She often sat in her room for hours, without saying a word.

    To attract(吸引) people to move back, the Town Hall decided to reopen the fair. One day, when I came back from school, I saw Grandma wearing her glasses, washing the dishes in the kitchen. With a big smile on her face, she looked much younger. She told me that her two nieces(侄女) would come. “They said the food I cooked was very delicious and they wanted to stay in my house again,” Grandma said happily. “They will stay here for one week and we can have a big party. That must be the busiest week I've had in years!”

    I suddenly realized that Grandma didn't want to be looked after. She wanted to be “useful” and helpful.

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