SCIENCE STUDY
Too much sleep is bad
小心啦！周末补觉会让你长肉哦。
The weekend is here! You can sleep longer and get up later than usual. But is it a good thing to sleep longer during weekends?
- 对本期电子报订户、有效期内的VIP教师会员和本学期初一尊享卡用户，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。
