题目

某豌豆种群中，AA，Aa和aa基因型的个体依次占25%、50%、25%．若该种群中的aa个体没有繁殖能力，则自然状态下随机交配，理论上，下一代AA：Aa：aa基因型个体的数量比为（）      A．3：3：1              B． 4：4：1          C．   1：2：0        D． 3：2：1 答案：D 请根据下面的任务说明和写作要求，以Should Students Play Computer Games？为主题写一篇150词左右的英语短文。 [任务说明]请认真阅读下面的短文，然后完成以下的任务。 1．题目自拟。 2．概括短文的内容要点，该部分的词数为30字左右。 3．就“中学生该不该玩网络游戏”这个主题发表你的看法，该部分的词数为120字左右。 4．你可以使用实例或其它论述方法支持你的论点，也可以参照阅读材料的内容，但不要抄袭阅读材料中的句子。 　　Every afternoon hundreds of thousands of youths flood Internet cafes, switch on game consoles(游戏机), or otherwise sit down to involve themselves in intense fantasy worlds．I’m talking about video games; games like Counter Strike, Diablo, Smash Brothers or Halo．These games can be fun and exciting but we need to watch out when this pastime becomes an addiction． 　　Games are often exciting and dramatic, but they generally aren’t very intellectual．We don’t learn as much from them as we would simply reading a book and spending too much time playing then can take away from our study time．We need to remember that we’re students first and foremost．Nothing should ever get in the way of proper studying． 　　Video games can also be a bad influence on younger children who may be watching．Many video games are violent and the object in most of them is to kill the other player(s)．This does not send the right message to the children who need to be told that violence is not acceptable and need to be taught how to handle situations maturely(成熟的)．Even if we do decide to sit down and play a violent video game, we need to make sure that it is not influencing the younger children around us．