阅读理解
    American people like to say “Thank you” when others help them or say something kind to them. People of many countries do so, too. It is a very good habit.
　You should say “Thank you” when someone passes you the salt on the table, when someone walking in front of you keeps the door open for you, when someone says you have done your work well, or you have bought a nice thing, or your city is very beautiful. “Thank you” is used not only between friends, but also between parents and children, brothers and sisters.
　　“Excuse me” is another short sentence they use. When you hear someone say so behind you, you know that somebody wants to walk past you without touching(触摸) you. It's not polite(礼貌) to break (打断) others when they are talking. If you want to speak to one of them, say “Excuse me” first, and then begin talking. You should also do so when you begin to cough(咳嗽)  or make any noise before others.
　　Let's learn to say “Thank you” and “Excuse me”.

选词填空。

鲁提辖回到下处，急急____(卷 拿 找)了些衣服盘缠，细软银两，但是旧衣粗重都____(弃 丢 扔)了；____(提 拿 扛)了一条齐眉短棒，____(窜 奔 走)出南门，一道烟____(走 跑 逃)了。

中医常通过“切脉”诊断疾病，选择的血管是静脉。

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鸣机夜课图记

【清】蒋士铨

      铨四龄，母日授四子书①数句。苦儿幼不能执笔，乃镂竹枝为丝断之，诘屈作波、磔②点画，合而成字，抱铨坐膝上教之。既识，即拆去。日训十字，明日，令铨持竹丝合所识字，无误，乃已。至六龄，始令执笔学书。

      记母教铨时，组绣纺③绩之具，毕陈左右；膝置书，令铨坐膝下读之。母手任操作，口授句读，咿唔之声，与轧轧相间。儿怠，则少加夏楚④，旋复持儿而泣曰：“儿及此不学，我何以见汝父！”至夜分，寒甚，母坐于床，拥被覆双足，解衣以胸温儿背，共铨朗诵之；读倦，睡母怀，俄而母摇铨曰：  “可以醒矣！”铨张目视母面，泪方纵横落，铨亦泣。少间，复令读；鸡鸣，卧焉。

     【注释】①四子书：《大学》、《中庸》《论语》、《孟子》。②波、磔（zhé）：汉字书写笔画。③组绣纺：即编织结线。④夏（jiǎ）楚：用于责打的大条等。

设$x,y\in R,$且x+y=5,则$3^x+3^y$的最小值是(      )