Historically, main material for making tables has been wood, but metal and stone have also been used.
A. the; the
B. the; /
C. /; the
D. /; /
网友回答
A. the; the
(答案→)B. the; /
C. /; the
D. /; /
解析：考查定冠词的用法。main material后面有修饰语for making a table，因此是特指，加定冠词，后面的metal和stone表示材料，都是物质名词，不加冠词。