it was along the mississippi river( )mark twain spent much of his childhood. A how B which C that D

题目

it was along the mississippi river( )mark twain spent much of his childhood. A how B which C that D
it was along the mississippi river( )mark twain spent much of his childhood. A how B which C that Dwhere,答案是C.我想问“along the mississippi river”在句中什么成分?以及为什么选C

答案

along the mississippi river,地点状语.
mark twain spent much of his childhood已经成为完整句子,因此前面部分考虑是状语.将It was和括号里的词去掉,成为Along the mississippi river mark twain spent much of his childhood.是个完整的句子,因此这一句是强调句式.强调句式用that.
如果题目改为it was the mississippi river( )mark twain spent much of his childhood,那么就应该选where了.因为去掉It was和括号之后,不成一个完整句子,因此是从句而不是强调句.