This is the first time in their to ski on the ApLs.A. life B. lifes C. lives

问题补充：

This is the first time in their to ski on the ApLs.

A. life B. lifes C. lives

答案：

解析：考查名词。句意：这是他们第一次在ApLs.滑雪。但我个人认为此题A也是对的。