前不久，中央电视台报道了贵州十岁男孩独自照顾重病妈妈的故事，引起社会极大反响。假如你是某校高三学生李华，请根据以下要点用英语向某英语报社写一封信。1、呼吁社会爱心捐助；2、学会感恩；3、结合实际谈谈你的看法。注意：1、信的开头和结尾已给出，不记入总词数；2、可根据内容要点适当发挥；词数120个左右。

Dear editor ,

I’m a  student of Senior Three . Not long ago , from CCTV, I learned that a ten-year-old boy in Guizhou was taking care of his seriously sick mother in hospital alone , by which I was deeply moved ….

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Yours sincerely ,

Li Hua

关于在下列四种化合物的化学组成的叙述，正确的是（）

A.①是腺嘌呤；①与④相同

B.②是腺苷；①比②多了脱氧核糖

C.③是腺嘌呤核糖核苷酸；③与④相同

D.④腺嘌呤；①比④多了核糖