人体成熟红细胞没有细胞核、精子中细胞质很少，这些细胞的寿命都很短，这一事实体现了（　　）

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(∧)，在其下面写出该加的词。

删除：把多余的词用斜线(＼)划掉。

修改：在错的词下面划一横线，并在该词下面写出修改后的词。

注意：1）每处错误及其修改均仅一词；

      2）只允许修改10处，多者（从第11处起）不计分。

    Last Friday afternoon, our class was invited an old craftsman to teach us how to making dough figurines (面人). When the craftsman came into the classroom, we gave him warm welcome and two boys helped him with the tool box. First, he shows us the basic steps and skills of making dough figurines. We stood around him or watched attentively. Then we started to have a try himself. The old man walked around and helped us patient. Finally, we put the figurines we made on the table and took pictures with the old craftsman. Looking on the figurines, we were all very exciting. We hope we can have more activity of this kind!

读某生态工业园区示意图，完成问题。

把线段比例 改写成数值比例尺是____，从图上量得A、B两地的距离是5.5厘米，A、B两地的实际距离是____千米．

    There are purple clothes, purple handbags, purple bicycles, purple furniture, even purple computers! So purple is one of the most1colors today. But in the past, purple was a very expensive and unusual color. Let's take a look at the rich2of the color purple.

    Some scientists believe that the first plants to appear on Earth over 500 million years ago3looked purple, not green. Plants today are green because4use green chlorophyll (叶绿素) to produce energy.5these early plants probably used something called retinal, which is a dark purple color.

    During the time of the roman Empire (37 BC-476 AD), it was very6to make purple dye (染料). The dye came from sea snails (海螺) .But10.000 dead sea snails7you just one gram (克)of purple dye… as well as a very bad smell! This8purple dye was called Tyrian purple, and it was the preferred9of emperors.

    In 16th--century England, purple was10for the king's family members. Queen Elizabeth Is clothes were purple, but ordinary people were not allowed to11the color.

    In 1856. William Perkin, an 18-year-old12student, noticed something strange while doing an experiment (实验). The chemicals (化学药品) he used to clean his instruments13with the chemicals he used in his experiment and produced a bright purple color. This14Perkin to start a company using this chemical mixture to make purple dye. The dye was much15than sea snail dye. Thanks to Perkin, now anyone can afford to wear purple clothes.