在音乐课上，老师教我们用'si'来代替音阶中的第七个音'ti'。

In music class, the teacher taught us to use ___si instead of 'ti' for the seventh note of the scale.

是的，今晚能借你的车用一下吗？

___Yes, can I borrow your car tonight?

这款智能手表采用了Si材料，既轻便又耐用。

This smartwatch uses ___Si material, making it lightweight and durable.