题干

如图,在△ABC中,∠C=90°,AC=BC=4,D是AB的中点,点E、F分别在AC、BC边上运动(点E不与点A、C重合),且保持AE=CF,连接DE,DF,EF.在此运动变化的过程中,有下列结论:
①△DFE是等腰直角三角形;
②四边形CEDF不可能为正方形;
③四边形CEDF的面积随点E位置的改变而发生变化;
④点C到线段EF的最大距离为 2
其中正确结论的个数是(    )

A:1个

B:2个

C:3个

D:4个

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B

同类题1

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送老师一捧叫“爱”的插花

    鲜花是美的代名词,是情的寄托,也是生命的象征。

    教师节要到了,让我们走进花卉市场,把最美丽的鲜花献给我们敬爱的老师,祝老师“节日快乐”!

    在人们的印象中,向日葵也叫太阳花,灿烂的花朵代表光辉和高尚;粉色康乃馨表达敬意与温馨;巴西木叶与春芋叶衬托出蓬勃的生机。那就买下向日葵、康乃馨、巴西木叶和春芋叶吧,再买一个方形的陶制花盆,插出名为“高尚”的盆花,连同那份美丽的心情和由衷的敬意,送给值得自己敬佩的老师。

    用一捧康乃馨做主花,陪衬着满天星和一片龟背竹,包上锡纸,比喻老师为人师表,事业有成。龟背竹既象征老师的宽阔胸怀,也象征自己生机盎然的进取意志,是拥抱成功的意义所在。用彩带精心地将花扎起来,起个名字叫“你心我心”,送给敬爱的老师,花语脉脉,表达相知的欣慰。

    虎头兰是高贵和富有的象征,用其做主花讴歌老师的品德高尚和知识渊博,最贴切不过了,鸢(yuān)尾配天冬草,更显得雅致和清纯,其中的情趣就尽在不言中了。精心扎出的这一捧鲜花叫做“恩师”吧,这是教师节最好的礼物。或者买下盛开的百合,它象征着恩师正如日中天,业绩辉煌。而且百合花的花香清淡宜人,默默散放,就像老师那种默默奉献的精神,买一只草编篮插起来,取名叫作“桃李满天下”,隆重地送到学校去,让老师们个个看了笑逐颜开。

同类题2

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    I loved my aunt Suzy. She was such a kind old lady. I loved going to her house on holiday. She had been sick for the last few years and, though my job had taken me away across the town, I tried to visit her as much as possible. I helped with the shopping, the cooking and the cleaning and taking her pet cat Mazy to the vet.

    Sad as her passing away was, what happened to Mazy was even more worrying. Because aunt Suzy had no children, there wasn't anyone who seemed to care for her beloved cat friend. I would have taken her in a short time, but my apartment doesn't allow pets. First, we talked with her neighbors. Mr. Jenkins, who was alone and lived across the street, wasn't interested. Joe and Sally who lived next door had a small child with serious skin allergies(过敏症). My aunt's best friend Molly who had lived just down the road was unable to take care of herself as she had serious health problems.

    Second, we thought about our family members. My brother Bobby and his wife Jill were eliminated at once as they aren't cat people. My cousin in California was a bit interested, but we weren't sure about the trip as Mazy was nearly as old as my aunt (in cat years!). Finally, we came to the local humane society to see whether they would be able to help her find a new home. The problem was that most people and families only welcomed a smart little cat into their home, not a dull old one.

    In the end, we had to put Mazy to sleep. I had spoken with the vet and realized it was possible for the best. It was so hard to lose aunt Suzy and then have nowhere for Mazy to live. A few months went by and I had gone to my aunt's house to clear out some of her belongings. I happened to see her mailman. Jerry and we started to talk about my aunt when he asked about Mazy. I told him that we had to put Mazy to sleep because we couldn't find a home for her. Jerry got really quiet. “I promised Suzy that if anything ever happened to her, I'd take care of Mazy”, he said sadly. “Suzy always said she'd told her lawyer the arrangement.”

    Hearing this, my heart sank to my feet and I almost cried. The saddest part, I realized, was this all could have been avoided. I guess we were just so busy in those final months that we didn't think about it. We could have called my aunt's lawyer to take care of it in less than 10 minutes. I'll never forgive myself for not thinking of it sooner. And I'll never forgive myself for losing Mazy.