单选题
The plumber conducted a thorough______ of how much it would probably cost to replace the old water pipes in Ms. Kent's apartment.
【正确答案】
A
【答案解析】解析：空格处所填单词作及物动词conducted的宾语，应选择可与不定冠词a连用，同时可以被形容词thorough修饰的名词。故(A)inspection(调查)为正确答案。动名词(D)inspecting不能和不定冠词a连用，且只能被副词修饰而不能被形容词修饰。动词(B)和(C)都不能放在名词的位置上。