已知关于x、y的方程组 $\{\begin{array}{c}x-y=a\text{+}3\\ 2x+y=5a\end{array}$ ， $a$ 为常数．

    【甲】元丰六年十月十二日夜，解衣欲睡，月色入户，欣然起行。念无与为乐者，遂至承天寺，寻张怀民。怀民亦未寝，相与步于中庭。庭下如积水空明，水中藻荇交横，盖竹柏影也。何夜无月？何处无竹柏？但少闲人如吾两人者耳。《记承天寺夜游》

    【乙】崇祯五年十二月，余住西湖。大雪三日，湖中人鸟声俱绝。

    是日更定矣，余拏一小舟，拥毳衣炉火，独往湖心亭看雪。雾凇沆砀，天与云与山与水，上下一白。湖上影子，惟长堤一痕、湖心亭一点，与余舟一芥、舟中人两三粒而已。

    到亭上有两人铺毡对坐一童子烧酒炉正沸。见余大喜，曰：“湖中焉得更有此人！”拉余同饮，余强饮三大白而别。问其姓氏，是金陵人，客此。

    及下船，舟子喃喃曰：“莫说相公痴，更有痴似相公者！”《湖心亭看雪》

   Hello, boys and girls. My name is Kangkang. I’m from Tianjin. I’m No.1 middle school.
   My mother works in No.1 middle school. She teaches Chinese. My father is a doctor in a hospital. They both work hard.
   On Sunday my mother and I often do some shopping. My mother likes shopping a lot. We will go shopping this Sunday afternoon. My mother says she will buy me a red coat. But I don’t like red. I want a yellow one. My mother says yes to me. I am happy.
   My father doesn’t like shopping at all. He likes animals best. He often takes me to the zoo. My favorite animal is the panda. I think panda are very cute. This Sunday morning my father will go to the zoo with me.
   I love my parents very much. They love me, too. I have a happy family.