题干

如图,基因组成是aa的枇杷枝条①,嫁接到基因组成为AA的砧木②上,所结枇杷的性状表现和基因组成分别为(    )

A:①的性状,AA

B:①的性状,aa

C:②的性状,aa

D:②的性状,Aa

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答案(点此获取答案解析)

B

同类题1

   A 10-year-old boy decided to learn judo though he had lost his left arm in a car accident. The boy was doing well, so he couldn't understand why, after three months of training, the master had taught him only one move.
   “ Master,” the boy finally asked, “shouldn't I be learning more moves?"“ This is the only move you know, but this is the only move you'll ever need to know,” the teacher answered.
   Several months later, the teacher took the boy to his first competition. Surprising himself, the boy easily won his first two matches. The third match proved to be more difficult, but after some time, his opponent (对手) became impatient and charged; the boy skillfully used his one move to win the match. Still amazed by his success, the boy was now in the final.
  This time, his opponent was bigger, stronger, and more experienced. Soon after the match started, the boy seemed to lose. Thinking that the boy might get hurt, the judge called a time-out. He was going to stop the match when the teacher appeared. “ No,” the teacher said, “Let him continue.” A short time after the match carried on, his opponent made a careless mistake. At once, the boy used his move to pin (压住) him. The boy won the match and the competition.
  On the way home, the boy asked the teacher what was really in his mind. " Why could I win the competition with only one move?" The teacher answered. "First, you've mastered one of the most difficult throws in judo. Second, your opponent can only attack your left arm to win you.”
根据短文内容完成下面的表格,每空一词。

Title: One’s weakness can become his____ 
A boy had lost left arm, ____  he decided to learn judo
After three months of training, the master taught him only one move.
His first____ First three matchesHe won.
FinalHis opponent was bigger, ____  and more ____ .
At the ____ , the boy seemed to lose the match.
The judge was____  that the boy might get hurt and called a time-out.
His opponent made a mistake. The boy used his move and pinned him.
He became the ____  of the match.
____ 1. He had almost mastered one of the most difficult throws in all of judo.
 The opponent can win the match by ____  your left arm.

同类题5

阅读下文,完成小题
有那样一个下午
       不知为什么,这些天来,我常常想起那样的一个下午。
       那是一个夏日的午后,母亲要去给玉米喷药,喊我去,我不情愿地说:“我又不会喷药,让我去干什么?再说我还要看书呢!”
       “不是让你喷药。因为喷壶太沉,我背不上肩,让你去帮我往肩上送送喷壶。”母亲小心地说,“你可以带书去,坐在井边的树阴下看书。”
       我满脸不高兴,又实在想不出搪塞的理由,只好去了。
       没有一丝风,天热得正狠,玉米长得还不及膝,一脚便可以踩折一棵,所以走在田间需要分外小心。我帮母亲背上喷壶后,便坐在树阴下,毫无意识地看着她缓缓地在玉米的隙地间移动。
       喷药是玉米生长期间必须的一道劳动工序,就是用定量的药兑上定量的水装在喷壶里,然后左手操作压杠、右手挥动喷嘴,均匀而细致地为每一棵玉米镀上一层“保护衣”。喷壶灌满至少要三四十斤重,每次回来,母亲的背都是湿透透的,不知道是汗水还是药水。
       “下次不要背那么多了!”我说。
       “傻丫头,好不容易来回跑一趟,太少了不值得。”母亲说。
       “我也试试吧。”我的语气明显缺乏诚意——我实在畏惧喷壶这种充满了怪味的重物,可是我已经18岁了,目睹母亲的劳累而无动于衷,我又感到愧疚。
       “不用了。你不会。再说我已经沾了手,就别染上你了。”母亲说,“你看你的书吧。”
       我在心底暗暗长嘘了一口气,居然觉得如释重负。
       最后一壶药喷完的时候,已经夕阳西下了。
       “怎么样?热不热?”母亲边洗手边问。
       “还好,就是井边的蚊子太多了。”我很随意地说。
       “咬出疙瘩了吗?回家赶紧用清凉油抹抹。”母亲说。
       我们就这样有一句没一句地聊着闲话回了家。回家后的情形我已经记得不太清楚了,只知道母亲吃过饭后就一直躺在竹椅上,一睡一整夜,而我“搂”着电视机一直看到“再见”
       一晃多年过去了,母亲患脑溢血去世也已多年。冥冥之中,我一直清晰地记着这件我们母女生活中最平凡最微不足道的小事。
       其实,这不是一件小事。
       大千世界,父母对儿女的溺爱有各种各样的方式:富贵人家让儿女一掷千金,小康门户让儿女精吃细咽,而我母亲,一个拙辞讷言的农妇,一位年过半百的人母,对我最常见的溺爱就是那个盛夏午后田边井旁的清凉绿阴。
       18岁的我,身体懒惰,心灵肤浅,矫情地谦让之后便是坦然地享受。然而,即使是矫情地谦让,也让母亲感到满足,而我坦然地享受,更使她觉得安慰。
       天底下还有哪一种爱,和母亲的爱是一样的呢?
       “世上只有妈妈好,有妈的孩子像块宝,投进妈妈的怀抱,幸福享不了……”一向喜好咬文嚼字的我,曾经在多种场合对这首歌里“享不了”三个字的用法提出质疑,认为用得实在不规范,意思实在也是表达不到位。
       “怎么不到位?享不了就是享受不完的意思嘛!”一次,一位朋友对我反驳道。
       我怔住了,为自己的迂和愚感到无地自容。如此明白的话,我居然一直愚钝不解,就像那个下午,我坐在树下读一本早已忘记了名字的闲书,而母亲,却背着沉重的喷壶一步一步缓缓地走在玉米的缝隙中,竟然问我“热不热”!
       我眼泪涌了出来。我明白:对我的爱,母亲是一条奔腾不息的大河;对母亲的爱,我则是一条喧嚣浮躁的小溪,永远永远只能是她的支流。