Unisilicates
单硅酸盐类
🗣️ 情景例句
I have just begun to learn and my serve isn't very good.
我刚刚开始学习，发球不太好。
Times have changed.
此一时也，彼一时也。
but I lacked for nothing, for he was both father and mother to me.
但我却什么都不缺，他既当父亲又当母亲。