题干

流行性感冒的传染源、传播途径、易感人群分别是(    )

A:飞沫或空气,流感患者,抵抗力弱的人

B:飞沫或空气,流感患者,所有的人

C:流感患者,飞沫或空气,抵抗力弱的人

D:流感病毒,飞沫或空气,抵抗力弱的人

上一题 下一题 0.0难度 选择题 更新时间:2019-04-08 08:08:35

答案(点此获取答案解析)

C

同类题3

阅读下面的文章,完成下列各题

雪夜

(日本)星新一

    雪花像无数白色的小精灵,悠悠然从夜空中飞落到地球的脊背上。整个大地很快铺上了一条银色的地毯。

    在远离热闹街道的一幢旧房子里,冬夜的静谧和淡淡的温馨笼罩着这一片小小的空间。火盆中燃烧的木炭偶尔发出的响动,更增浓了这种气氛。

    “啊!外面下雪了。”坐在火盆边烤火的房间主人自言自语地嘟哝了一句。

    “是啊,难怪这么静呢!”老伴儿靠他身边坐着,将一双干枯的手伸到火盆上。

    “这样安静的夜晚,我们的儿子一定能多学一些东西。”房主人说着,向楼上望了一眼。

    “孩子大概累了,我上楼给他送杯热茶去。整天闷在屋里学习,我真担心他把身体搞坏了。”

    “算了,算了,别去打搅他了。他要是累了,或想喝点什么,自己会下楼来的。你就别操这份心了。父母的过分关心,往往容易使孩子头脑负担过重,反而不好。”

    “也许你说得对。可我每时每刻都在想,这毕业考试不是件轻松事。我真盼望孩子能顺利地通过这一关。”老伴儿含糊不清地嘟哝着,往火盆里加了几块木炭。

    突然,一阵急促的敲门声打破了这寂静的气氛。

    两人同时抬起头来,相互望着。

    “有人来。”

    房主人慢吞吞地站了起来,蹒跚地向门口走去。随着开门声,一股寒风带着雪花挤了进来。

    “谁啊?”

    “别问是谁。老实点,不许出声!”

    门外一个陌生中年男子手里握着一把闪闪发光的匕首。声音低沉,却掷地有声。

    “你要干什么?”

    “少啰嗦,快老老实实地进去!不然……”陌生人晃了晃手中的匕首。

    房主人只好转身向屋子里走去。

    老伴儿迎了上来:“谁呀?是找我儿子……”她周身一颤,后边的话咽了回去。

    “对不起,我是来取钱的。如果识相的话,我也不难为你们。”陌生人手中的匕首在炭火的映照下,更加寒光闪闪。

    “啊,啊,我和老伴儿都是上了年纪的人,不中用了。你想要什么就随便拿吧。但请您千万不要到楼上去。”房主人哆哆嗦嗦地说。

    “噢?楼上是不是有更贵重的东西?”陌生人眼睛顿时一亮,露出一股贪婪的神色。

    “不,不,是我儿子在上面学习呢。”房主人慌忙解释。

    “如此说来,我更得小心点。动手之前,必须先把他捆起来。”

    “别,别这样。恳求您别伤害我们的儿子。”

    “滚开!”

    陌生人三步两步蹿上楼梯。陈旧的楼梯发出吱吱呀呀的声音。

    两位老人无可奈何,呆呆地站在那里。

    突然,喀嚓一声,随着一声惨叫,一个沉重的物体从楼梯上滚落下来。

    房主人从呆愣中醒了过来,慌忙对老伴儿说:“一定是我们的儿子把这家伙打倒的。快给警察挂电话……”

    很快,警察们赶来了。在楼梯口,警察发现了摔伤了腿躺在那里的陌生人。

    “哪有这样的人,学习也不点灯。害得我一脚踩空。真晦气。”陌生人一副懊丧的样子。

上楼搜查的警察很快下来了。

    “警长,整个楼上全搜遍了,没有发现第二个人,可房主人明明在电话中说是他儿子打倒的强盗,是不是房主人神经不正常?” “不是的。他们唯一在上学的儿子早在数年前的一个冬天死了。可他们始终不愿承认这一事实。总是说,儿子在楼上学习呢。”

    谁也没有再说话。屋里很静,屋外也很静。那白色的小精灵依然悠悠然然地飞落下来……

同类题5

阅读下列短文,从每题所给的四个选项(A、B、C和D)中选出最佳选项。
      When an animal helps another animal,it usually gets something valuable in return. For a long time,many scientists thought that only people could act generously just because it feels good.
      However,a new study in Germany suggests that chimpanzees (an animal like a large monkey without a tail ) also do good things for no real reason. And so do children who are as young as 18 months of age. Maybe it is because humans and chimpanzees share an ancestor about 6million years ago.
      People and chimpanzees appear to develop such features without any other training,says Warneken,a scientist in Germany.
      Warneken and his partners worked on adult chimpanzees that live on an island in the African country of Uganda. They also worked with 18-month-old children in Germany. The researchers performed three experiments on the adult chimpanzees and two experiments on the kids. In the first animal experiment,a person tried to reach his arm into a cage to get a stick,but he couldn't reach it. A chimpanzee was in the cage,and it could reach the stick if it wanted to.
      Thirty-six chimpanzees took part in this experiment one by one,and no chimpanzee saw what the other chimpanzees had done. Even though the animals hadn’t met the person before,they usually took the stick and gave it to the person. What's more,they did this whether or not the person offered them bananas as a reward.
      In a similar experiment,36 children acted in a similar way. They helped the person reach the stick,whether or not they were offered toys for their help.
      Researchers did other experiments on chimpanzees and babies. No rewards were offered in either experiment. And still,both the chimpanzees and children went out of their way to help. Still,the new study is different from earlier findings. Researchers have found that chimpanzees don't give rewards of food to other chimpanzees,even if it costs them nothing to be generous.