成人英语三级考试

【单选题】The factory produces half a million pairs of shoes every year, 80% ______ are sold abroad.
A. of which
B. which of
C. of them
D. of that

网考网参考答案：A
网考网解析：
of表示部分与整体的关系，关系代词which表示half a million pairs of shoes。 查看试题解析出处>>