MAGIC WORLD
The Earth's big coat
地球的防晒衣-臭氧层
We all know that the sun is very hot. Why doesn’t it burn (晒伤) us? Maybe you will say it is because it’s so far away.
- 对本期电子报订户、有效期内的VIP教师会员和本学期小学尊享卡用户,我们开放所有内容:
- 如果您拥有以上权限,请点这里登录;
- 订阅电子报,请点这里;
- 激活VIP教师卡,请点这里;
- 激活21英语尊享卡,请点这里。