It was along the Mississippi River Mark Twain spent much of his childhood.
A. how
B. which
C. that
D. where
网友回答
A. how
B. which
(答案→)C. that
D. where
解析：句意：正是在密西西比河岸马克·吐温度过了他孩提时代的大部分时光。本题考查强调句。如果把It was以及that 去掉，原句就成了along the Mississippi River Mark Twain spent much of his childhood.句子仍然完整。