“Youth” is regarded by many people as a time in their life fun passion and imagination

问题补充：

“Youth” is regarded by many people as a time in their life fun, passion, and imagination seem limitless.

A. that

B. which

C. when

D. where

答案：

A. that

B. which

(答案→)C. when

D. where

解析：考查定语从句：句意：年轻似乎是人生中一段时间，那时快乐，热情和想象力似乎是无限的。这句话是定语从句，先行词是a time，定语从句中缺少时间状语，用when引导定语从句。选C。