问题补充：
I want to use the same tools used in your factory a few days ago.
A. as was
B. which was
C. as were
D. which
答案：
A. as was
B. which was
(答案→)C. as were
D. which
解析：as引导定语从句时通常构成such…as或the same…as固定搭配，其中such和same修饰其后的名词，as为关系代词，指代其前的名词引导定语从句。as在从句中可以作主语、表语或宾语。本题中as作从句的主语.
