题干

一个袋子中有5个大小相同的球,其中有3个黑球与2个红球,如果从中任取两个球,则恰好取到两个同色球的概率是(   )

A:15

B:310

C:25

D:12

上一题 下一题 0.0难度 选择题 更新时间:2016-01-08 06:56:20

答案(点此获取答案解析)

C

同类题2

散文阅读,回答1-5题。 

老师! 老师!  阎连科

     ①我又见着我的老师了,如朝山进香的人见到他自幼就心存感念的一位应愿之神。

     ②在今年正月,我回家奔三叔的喜丧事。在这闲空间,张老师到了我家里,坐在我家堂屋的凳子上。乡间室内的空旷和凌乱,分隔着我与老师的距离。相向而坐,喝着白水,削了苹果,说了很多旧忆的伤感和喜悦,诸如三十几年前在初中读书时,我的学习,我的作业,我的逃课。21教育网

③我老师张梦庚的一生,清寂中夹缠暖意,暖意里藏裹着刺骨的寒凉。

④生于上世纪的20年代末,老师读书辍学,辍学读书,反反复复,走在田埂与人生的夹道中,经历了抗战和解放战争,有了1949年的红旗飘扬,记忆中从来都是饥饿辛劳,土改时家里却忽然成了地主。好在,他终归识字,也有文化,祖国的乡村,也最为明白文化的斤两,虽然文化不一定就是尊严富贵,可让孩子们认字读书,能写自己的姓名和粗通算术,也是生活的部分必然。于是,老师就成了老师。从一个乡村完小到另一个乡村完小,从一个乡村中学到另一个乡村中学。直至改革开放后,他被调入县里的一所高中,做了教导主任,最后主持这个学校的工作。一晃就让他全部人生的金贵岁月,43个春秋的草木荣枯,都在布满土尘、青草蓬生的学校里荣枯衰落,青丝白染。 
  ⑤不知道老师对他的人生有何感想,从他写的一本《我这一生——张梦庚自传》的简朴小册里,读下来却是让人心酸胃涩,想到世事的强大和个人的弱小,想到命运和生命多么像流水在干涸沙地上蜒蜿涓涓,奔袭挣脱,流着流着,可终归无法挣脱干涸的吞没。最后的结局是,我们毕业了,老师白发了;我们中年了,老师枯衰了。我们成家立业了,而老师却在寂静的人生中,望着他曾经管教训斥抚疼过的学生们,过着忆旧的生活,想着那些他依然记得、可他的学生们早已忘却的往事。 
  ⑥还记得,初一时,他是我的班主任,又主教语文。一天酷暑,我家棉花地里蚜虫遍布,多得兵荒马乱,人心恐惧,我便邀了班里十几个相好的男同学,去帮我母亲捕捉蚜虫。自然,那一天教室里学生寥寥,老师无法授课而只能让大家捧书阅读。从棉花地里回校的来日上午,老师质问我为什么带着同学逃课,我竟振振有词地说,是带着同学去棉花地捉了半天蚜虫;竟又反问老师道,地里蚜虫遍布,我该不该去帮我母亲捕捉蚜虫?说蚜虫三天内不除掉去净,棉花就会一季无收,时间这样急迫,我家人手不够,我请同学们去帮半天,到底又做错了什么? 
  ⑦事情的结果,似乎我带同学们逃课捉虫正合校规事理,反让老师在讲台上一时有些哑言。回忆少时的无理取闹,强辞夺理,也许正是自己今天在写作中敢于努力把不可能转化为可能的开始。可是,现在,面对耄耋(mào dié,指年纪八九十岁)老人,给我一生养育呵护的父辈尊者,我心里三十几年不曾有的内疚,忽然如沙地泉水般汩汩地冒了出来。 
  ⑧我们就那样坐着喝水聊天,说闲忆旧,直至夕阳西下,老师执意要走,不无快意地说他的子女们都在外工作,孝顺无比。真是天应人愿,让一生坎坷、教书认真的老师,年老时,子女有成,学生有成,仿佛曲折的枯藤根须,终于也繁漫出了一片森林。 
  ⑨老师从我家离去时,是我扶他站起;离开院子时,是我扶他过的门槛;送至门口远去时,是我扶他过的一片不平不整的地面。我的父亲离开人世太早,扶着老师的时候,我就像扶着我年迈的父亲。望着村头远去的父亲般的老师,落日中他如在大地上移动的一棵年迈的树。直至他在村头缓缓消失,我还看见他在我心里走动的身影和慢慢起落的脚步,如同宁静里我在听我的心跳一样。 
  ⑩说不出老师哪儿伟大,可就是觉得他伟大。也许这个世界,凡人才是真正的伟大,而伟大本身,其实正是一种被遮蔽的大庸大俗吧。(选自《读者》2015.10有删改)


同类题4

根据短文理解,选择正确答案。

    I was feeling really down because my long-time friend had died. Then I started a six-week volunteering at a nursing home all day even Saturday. My duty was to serve the meal and clean up. One day I was told to go to Room 117 to make sure the patient was all right. I found a boy of eight sitting in bis bed watching a movie. I was shocked to see a child in this seemingly forgotten nursing home for the old. He was so small and weak that you had to look closely to find him. I grabbed his medical chart and found out :he had a terminal(绝症的) illness.

    We started to talk, and I found out that his family rarely visited, and all he did every day was watching TV I wanted to cry for him, and for my lost friend. As we talked, he had a smile on his face, and I asked him why and how he still managed to stay happy.

    He thought for a moment, and then said that too many people were dead even before they died. They walked around feeling that God had cursed(诅咒) them and they had nothing to live for.

    The boy said that he would not be like that. He woke 'every morning thankful to see another sunrise. He kept his window open so that he could smell the flowers and feel the heat of the sun. He also said that he had hope.

    "Too many people haven't seen much of that around here." He said, "Life is full of hope and we need to live life before it is gone."

    I don't know what happened to him. I guess he passed away, but his lesson lives on. I now wake up and live each day to the fullest. The key to life is not money or fame, but the lesson we learned from it.