题干

某课外小组的同学们实践活动中调查了20户家庭某月用电量,如下表所示:

用电量(度)

120

140

160

180

220

户数

2

3

6

7

2

则这户家庭用电量的中位数是____ 度.

上一题 下一题 0.0难度 选择题 更新时间:2011-12-14 12:16:42

答案(点此获取答案解析)

160

同类题2

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       A woman was walking her dog along a beach in New Zealand in late June when she saw something that looked like a white ball in the sand. It turned out to be a young Emperor penguin that was lost. At his age, he should have been close to Antarctic, swimming for fish and playing on the ice floes (浮冰). But this penguin started swimming north and just kept going.

       The penguin attracted a lot of attention in New Zealand. It has been 40 years since an Emperor penguin was last seen there. Researchers at the Department of Conservation were called in. They decided to watch the penguin closely, but not to disturb it in any way. Many New Zealanders came to Peka Peka Beach to look at the elegant penguin. They were careful to keep their dogs away from it so it wouldn't be frightened.

       The public nicknamed the animal Happy Feet. Researchers started to notice that Happy Feet didn't seem well. It turned out that he had been eating the sand from the beach, likely thinking it was snow.

       The public raised more than 11,000 pounds for an operation to get the sand out of his stomach. The operation was a success, and Happy Feet was taken to a zoo in Wellington, NZ. A group of experts met to decide how to help Happy Feet return to the wild.

        Last Sunday, they put him on a boat called the Tangaroa, in a specially built ice­filled box and took him out into the Southern Ocean, southeast of New Zealand. There, they released him into the ocean, which is his natural habitat. He took one last look at his human helpers and then dived into the ocean.

      “Emperor penguins spend their first five years at sea,” said Peter Simpson of New Zealand's Department of Conservation. “What happens now is up to the penguin.”

         Happy Feet was fitted with a satellite transmitter (信号发射器) so they can monitor his progress using the Internet. So far, the trackers shows that he swam northeast for a little while before getting his bearings and heading south.

同类题3

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      【甲】陈胜者,阳城人也,字涉。吴广者,阳夏人也,字叔。陈涉少时,尝与人佣耕,辍耕之垄上,怅恨久之,曰:“苟富贵,无相忘。”佣者笑而应曰:“若为佣耕,何富贵也?”陈涉太息曰:“嗟乎!燕雀安知鸿鹄之志哉!”

       二世元年七月,发闾左適戍渔阳,九百人屯大泽乡。陈胜、吴广皆次当行,为屯长。会天大雨,道不通,度已失期。失期,法皆斩。陈胜、吴广乃谋曰:“今亡亦死,举大计亦死;等死,死国可乎?”陈胜曰:“天下苦秦久矣。吾闻二世少子也,不当立,当立者乃公子扶苏。扶苏以数谏故,上使外将兵。今或闻无罪,二世杀之。百姓多闻其贤,未知其死也。项燕为楚将,数有功,爱士卒,楚人怜之。或以为死,或以为亡。今诚以吾众诈自称公子扶苏、项燕,为天下唱,宜多应者。”吴广以为然。

      【乙】项籍者,下相①人也,字羽。项籍少时,学书不成,去学剑,又不成。项梁②怒之。籍曰:“书足以记名姓而已,剑一人敌,不足学。学万人敌。”

       秦始皇帝游会稽,渡浙江,梁与籍俱观。籍曰:“彼可取而代也!”梁掩其口,曰:“毋妄言,族矣!”粱以此奇籍。籍长八尺余,力能扛鼎,才气过人,虽吴中子弟皆已惮籍矣。

       秦二世元年七月,陈涉等起大泽中。其九月,会稽守通谓梁曰:“江西皆反,此亦天亡秦之时也。吾闻先即制人,后则为人所制。吾欲发兵,使公及桓楚将。”是时桓楚亡在泽中。梁曰:“桓楚亡,人莫知其处,独籍知之耳。” 梁乃出,诫籍持剑居外待。

                                                                                                                                                                                             (《史记•项羽本纪》)

      【注】①下相:古县名,在今江苏宿迁境内。②项梁:项羽的叔父。