Many of -----are young and some are old

题目

Many of -----are young and some are old
A they B them C their D theirs
选择并解释!谢谢啦

答案

B
这里需要宾语,they做主语
their和theirs都是他们的,如果放进去好像缺什么东西
如果语感好的话能顺着读下来.加油