—Believeitornot，mysisterandIaretwins.—Oh，youmusthavehad...

來源：國語幫 4.87K

—Believe it or not，my sister and I are twins.

—Oh，you must have had the case________you were taken for your sister.

A．which　 B．whose

C．where　 D．whom

C 解析：　考查定語從句。語意表示你肯定有過你被誤認為是你姐姐的情況。where you were taken for your sister是定語從句，修飾先行詞the case，表示的是抽象地點，where可用in which替換。