Calsil
硅酸钙盐
🗣️ 情景例句
We will help your children in learning lessons in their free time.
我们可以帮助您的孩子在他们空闲时学习功课。
No, it isn't. It's a bus.
不，那是一辆公共汽车。
What was wrong?
怎么啦？