已知甲、乙两组数据的平均数分别是甲=80，乙=90，方差分别是S甲2=10，S乙2=5，比较这两组数据，下列说法正确的是A.甲组数据较好B.乙组数据较好C.甲组数据的

Although in 1947 we were still very new to the atomic age, we knew about mushroom clouds. A huge crack (裂缝) spread across the library wall upstairs, sending teachers and 31 screaming down the hall.
Had a new world war started? Pale­faced, our young science teacher quickly 32 us for a fire drill. We huddled (卷缩) in little groups on the beach side of the school grounds and 33 the spreading cloud darken the bright spring sky.
Rumors flew every which way， 34 two hours would pass before we got the full story. One rumor we heard was that the Texas City Monsanto Chemical plant had 35 ； children whose parents 36 there began to cry.
I 37 —that was where my father was working that day.
The school bell called us back inside, and we were dismissed (解散) to 38 our way home the best way we could. I'd walked a quarter of the three­mile trip to my home 39 a car horn frightened me to 40 . My Uncle Barney 41 alongside me in his old Ford. The instant I saw him, I knew my father 42 . Otherwise, Papa would have 43 for me himself.
As if in slow motion from a great distance, Uncle Barney motioned for me to 44 . Numb with grief, I crawled into the back 45 . I barely took notice of the man sitting there, and didn't recognize him until he 46 me. When Papa put his strong arms around me, I forgot for a moment that Cherokees aren't supposed to 47 .
Many of my fellow students lost their 48 in the explosion. Tragedy would one day come to our 49 ， as it inevitably (不可避免地) comes to all, but one day Texas City blew up, it miraculously (奇迹般地) passed us by. Because he lost his keys on that April morning, as he explained, my father lived for 50 32 years—we were to have a second lifetime forever.
【小题1】A．headmasterB．studentsC．workersD．books【小题2】A．organizedB．orderedC．madeD．asked【小题3】A．heardB．smelledC．watchedD．felt【小题4】A．whenB．asC．as ifD．although【小题5】A．blown upB．been closedC．been openedD．been on fire【小题6】A．livedB．workedC．studiedD．visited【小题7】A．smiledB．frightenedC．frozeD．worried【小题8】A．makeB．feelC．pushD．find【小题9】A．whenB．whileC．asD．for【小题10】A．decisionB．attentionC．feelingD．expression【小题11】A．pulled upB．pulled outC．pulled inD．pulled off【小题12】A．was thereB．was hereC．was goneD．was alone【小题13】A．goneB．comeC．leftD．stopped【小题14】A．get offB．get overC．get throughD．get in【小题15】A．seatB．chairC．stoolD．bag【小题16】A．looked atB．helpedC．reached forD．called on【小题17】A．cryB．laughC．exciteD．shout【小题18】A．teachersB．relativesC．friendsD．parents【小题19】A．classB．familyC．schoolD．house【小题20】A．otherB．othersC．anotherD．the otherB

(答案→)B 解析：文章主要讲述了作者的父亲在自己工作的工厂爆炸中幸存，作者能再次看见父亲真是令人高兴。【小题1】B 从上文的teachers可知，应该是学生，故B正确。【小题2】A organize组织；order命令；make让；ask请求；句意：老师很快组织我们进行消防演习。根据句意可知A正确。【小题3】C 从下文的the spreading cloud darken the bright spring sky可以看出，应该是观看，故C正确。【小题4】D 此处是让步状语从句。故萱although.【小题5】A 句意表示化工厂爆炸了，blow up爆炸符合题意。A正确。【小题6】B 从上文的the Texas City Monsanto Chemical plant had…下文的began to cry看出答案，故B正确。【小题7】C 那也是我父亲工作的地方。我呆住了，frighten恐吓，要接宾语。而这里用不及物动词。Freeze凝固，僵硬符合题意。C正确。【小题8】D 从上文的化工厂爆炸看，学生是找回家的恶露，make one’s way前进；feel one’s way摸索着前进；push one’s way挤出一条路；find one’s way找到一条路，故D正确。【小题9】A 句意：我在回家的路上走了四分之一，这是一辆轿车的喇叭声吓着我了，when正在这时；符合句意，A正确。【小题10】B 从上文的轿车喇叭吓着我看出答案。故B正确。【小题11】A 从下文的alongside me in his old Ford看出车停了下来，pull up停下来，符合句意，A正确。【小题12】C 从下文的otherwise, papa would have…for me himself,猜出父亲走了，不在了，故C正确。【小题13】B 结合上一题，要不父亲不会亲自来的。Come符合句意。B正确。【小题14】D 从上文叔叔把车停下来，让作者上车，get in上车，符合句意，D正确。【小题15】A 从I crawled into the back可知是车的后座。A正确。【小题16】C 句意：直到父亲伸手摸我，我才恩出他来。Reach for伸手去拿。【小题17】A 句意：Cherokee是不应该哭泣的。从前面的children whose parents…there began to cry看出答案。故A正确。【小题18】D 从上文的children whose parents…there began to cry看出是他们的父母，故D正确。【小题19】B 悲剧有一天也会降临到我的家庭，因为父亲也在那个工厂工作。故B正确。【小题20】C 父亲在一次免遭灾难，所以又过了32年，another再，又；符合句意，故C正确。

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我也是这个答案

D解析分析：比较两组数值哪组较好，不只要比较平均数，还要比较方差，方差越小数据的波动越小．由此可得出