题干

下列生物中,为单细胞生物且细胞内没有成形细胞核的是(  )

A:霉菌

B:酵母菌

C:细菌

D:病毒

上一题 下一题 0.0难度 选择题 更新时间:2014-10-21 11:56:23

答案(点此获取答案解析)

C

同类题1

根据题意,选择恰当的选项填入横线中。

How to become a better runner

  This is meant for runners in high school .If you want to become a better runner, then here are several things you can do.

  Connect with your team if you are new. ____ .You can ask them for advice and hang out with them outside of practice!

  If you have a workout,don’t slack off(松懈) ever.This will never improve your performance .

____ .I know some people say they do it just to stay in shape,but if you want to stay in shape you have to work for it!

  Run 6 out of  the 7 days in a week, but don’t work out on your days off. You need to relax.

____ .It dosn’t have to be as much as you would run during practice, but you should still exercise so that you don’t get out of shape.

  If you are injured, do not run. ____ . It’s common to get shin splints(小腿酸痛), so if this happens to you ,just take a break from running. It will actually make you better once you start running.

    ____ .It allow you to form a relationship with other people like a family. If you take time to become a better runner, you will be physicaaly and mentally(精神上地) stronger.


A, It takes much of your time.

B,Running is more than a sport.

C,Running can make problems worse.

D,It is an experience that you will never forget.

E,But if you are having a long break , you should still run.

F,Remember that you are supposed to run in a running sport.

G,It helps you realize that there is more to just the sport to look forward to.

同类题3

阅读文段,回答问题。

走向虫子

      一只八条腿的小虫,在我的手指上往前爬,爬得极慢,走走停停,八只小爪踩上去痒痒的。停下的时候,就把针尖大的小头抬起往前望。然后再走。我看得可笑。它望见前面没路了吗?竟然还走。再走一小会儿,就是指甲盖,指甲盖很光滑,到了尽头,它若悬崖勒不住马,肯定一头栽下去。我正为这粒小虫的短视和盲目好笑,它已过了我的指甲盖,到了指尖,头一低,没掉下去,竟从指头底部慢慢悠悠向手心爬去了。

      这下该我为自己的眼光羞愧了,我竟没看见指头底下还有路。走向手心的路。

      人的自以为是使人只能走到人这一步。

      一次我看见一只蜣螂滚着一颗比它大好几倍的粪蛋,滚到一个半坡上。蜣螂头抵着地,用两只后腿使劲儿往上滚,费了很大劲才滚动了一点点。而且,只要蜣螂稍一松劲儿,粪蛋有可能再滚下去。我看得着急,真想伸手帮它一把,却不知蜣螂把它弄到哪。我朝四周看了一圈也没弄清哪是蜣螂的家,是左边那棵草底下,还是右边那几块土坷垃中间。不清楚蜣螂在滚这个粪蛋前,是否先看好了路,我看了半天,也没看出朝这个方向滚去有啥去处。

或许我的想法天真,蜣螂根本不想把粪蛋滚到哪去。它只是做一个游戏,用后腿把粪蛋滚到坡顶上,然后它转过身,绕到另一边,用两只前爪猛一推,粪蛋骨碌碌滚了下去,它要看看能滚多远,以此来断定是后腿劲大还是前腿劲大。谁知道呢?反正我没搞清楚,还是少管闲事。我已经有过教训。

      那次是一只蚂蚁,背着一条至少比它大二十倍的干虫,被一个土块挡住。蚂蚁先是自己爬上土块,用嘴咬住干虫往上拉,试了几下不行,又下来钻到干虫下面用头顶,竟然顶起来,摇摇晃晃,眼看顶上去了,却掉了下来,正好把蚂蚁碰了个仰面朝天。蚂蚁一骨碌爬起来,想都没想,又换了种姿势,像那只蜣螂那样头顶着地,用后腿往上举。结果还是一样。但它一刻不停,动作越来越快,也越来越没效果。

      我猜想这只蚂蚁一定是急于把干虫搬回洞去。洞里有很多孤老寡小在等着这条虫呢。我要能帮帮它多好。正好附近有一只闲转的蚂蚁,我把它抓住,放在那个土块上,我想让它站在上面往上拉,下面的蚂蚁正拼命往上顶呢,一拉一顶,不就上去了吗?

      我又想错了。那只忙碌的蚂蚁好像感到身后有动静,一回头看见这只,二话没说,扑上去就打。这只被打翻在地,爬起来仓皇而逃。也没看清咋打的,好像两只牵在一起,先是用口咬,接着那只腾出一只前爪,抡开向这只脸上扇去,这只便倒地了。

      那只连口气都不喘,回过身又开始搬干虫。我真看急了,一伸手,连干虫带蚂蚁一起扔到土块那边。我想蚂蚁肯定会感激这个天降的帮忙。没想它生气了,一口咬住干虫,拼命使着劲,硬要把它再搬到土块那边去。

      我又搞错了。也许蚂蚁只是想试试自己能不能把一条干虫搬过土块,我却认为它要搬回家去。也许都不是。我这颗大脑袋,压根儿不知道蚂蚁那只小脑袋里的事情。