写作练兵
假如你发明的“飞行单车”在学校科技节中获奖并被推荐参加一个国际青少年科技展览，请用英语写一篇词数100左右的短文介绍你的发明。
写作要点：
1.(1)有两个轮子和两个翅膀；(2)可行驶于地面和空中，可拍照；(3)速度快，使用太阳能，环保；
2.介绍改进计划(1—2点)；
3.阐述作用。
My invention is a flying bike.

My invention is a flying bike. It has two wheels and two wings. It is fast, convenient and green. It has a top speed of 100 km/h. You can go to farther places in a short time. It can run on the land and fly in the air. If you shout "fly", the bike will turn into a plane in 30 seconds. Then you can fly in the air. You will be as free as a bird. It can take photos, too. Instead of petrol, the bike uses solar power, so it will not pollute the air.
I will add a seat behind it so that it can carry two persons.
My invention will help people live a better life in the future.

【分析】首先明确写作任务是介绍获奖的飞行单车，需覆盖三个写作要点：1. 外形、功能、能源；2. 改进计划；3. 作用。写作思路：先点明发明名称，再依次描述外形（两个轮子和两个翅膀）、核心功能（地面/空中行驶、拍照、速度快）、能源（太阳能，环保），接着说明改进计划（添加座位可载两人），最后阐述对未来生活的作用，确保词数符合要求，语言简洁准确。
【解析】按照写作要点依次展开：1. 介绍飞行单车的外形（two wheels and two wings）、功能（可在地面行驶、空中飞行，能拍照，最高时速100km/h）、能源（使用太阳能，环保无污染）；2. 改进计划：在车后添加一个座位，可载两人；3. 作用：帮助人们未来过上更好的生活。语句通顺，符合英语表达习惯，词数约100，满足要求。
【答案】My invention is a flying bike. It has two wheels and two wings. It is fast, convenient and green. It has a top speed of 100 km/h. You can go to farther places in a short time. It can run on the land and fly in the air. If you shout "fly", the bike will turn into a plane in 30 seconds. Then you can fly in the air. You will be as free as a bird. It can take photos, too. Instead of petrol, the bike uses solar power, so it will not pollute the air.
I will add a seat behind it so that it can carry two persons.
My invention will help people live a better life in the future.
【知识点】英语说明文写作、科技话题英语写作
【点评】本文紧扣写作要求，全面覆盖所有要点，结构清晰，语言流畅自然，准确介绍了发明的特点、改进计划及作用，符合国际青少年科技展览的介绍语境，是一篇优秀的英语短文。
【难度系数】0.6