xc

The teacher wrote xc on the board and asked what number it meant.

用法提示：这里的 xc 作为名词，指代罗马数字中的九十。

When you see xc in this old text, read it as the number ninety.

用法提示：xc 在句中作名词，表示数量九十。

He circled xc in the list because it was equal to ninety.

用法提示：此处的 xc 是名词，作“九十”这个数来使用。