Garbage collector Jose Gutierrez is 53 years old. When he was young his family was too poor to keep him in school. Jose left school when he was in Grade Two, but that did not stop him having a love for reading.

    Jose said he got the love of reading from his mother. “She read me stories every night,” said Jose. He hopes that every poor child in his city can have books to read. Jose started saving books from garbage twenty years ago. Every day he drives the garbage truck through the city's rich neighborhoods to get old books. Now there are about 20,000 books in Jose's small house. It is already a famous library.

    Books are rare things for children in poor neighborhoods. New books are too expensive. There are nineteen libraries in Bogota, the city where Jose lives, but they are all far from poor neighborhoods.

    Now Jose is famous in Bogota. Many people give old books to him. Jose plans to make more libraries to help more children.

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      ［甲］先帝知臣谨慎，故临崩寄臣以大事也。受命以来，夙夜忧叹，恐托付不效，以伤先帝之明，故五月渡泸，深入不毛。今南方已定，兵甲已足，妆奖率三军，北定中原，庶竭驽钝，攘除奸凶，兴复汉室，还于旧都。此臣所以报先帝而忠陛下之职分也。

                                                                                                                                             （节选自诸葛亮《出师表》）
      ［乙］臣受命之日，寝不安席，食不甘味。思惟北征，宜先入南。故五月渡沪，深入不毛，并日而食。臣非不自惜也，顾王业不可偏安于蜀都，故冒危难，以奉先帝之遗愿，而议者谓为非计。今贼适疲于西，又务于东，兵法乘劳，此进趋之时也。

                                                                                                                                              （节选自诸葛亮《后出师表》）

【实验步骤】

①选取在实验种植区(与大田生产条件基本一致)处于快速生长期的大小、长势一致的甘蔗植株，每隔10天左右定时（每天上午10:00）取样3个茎尖并固定。

②制作茎尖细胞分裂临时装片:切取茎尖→用卡诺溶液固定5〜24h，再转入体积分数为70%的酒精保存→解离→步骤A→用改良苯酚品红染液处理8〜16min→压片。

③制作装片，观察、统计细胞总数及处于分裂中期的细胞数，并计算细胞分裂指数（有丝分裂中期细胞数与细胞总数的比值）。

【实验结果】

请回答下列问题。

某超市从厂家以每件21元的价格购进一批商品，该超市可以自行定价，但物价局限定每件商品加价不能超过售价的20%，则这批商品的售价不能超过____元.