It was along the Mississippi River Mark Twain spent much of his childhood.A. howB. whichC

问题补充：

It was along the Mississippi River Mark Twain spent much of his childhood.

A. how

B. which

C. that

D. where

答案：

A. how

B. which

(答案→)C. that

D. where

解析：此句为强调句，强调状语“along the Mississippi River”还原后应为“Mark Twain spent much for his childhood along the Mississippi River.”