问题
选择题
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．/; /
答案
答案：B
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。