So far all cloned animals have suffered from some different serious disorders, dying soon after birth.
A. many of which
B. many of whom
C. many of them
D. many of that
网友回答
A. many of which
B. many of whom
(答案→)C. many of them
D. many of that
解析：本题考查独立主格结构。分析句中可知，后面一句没有谓语动词，故非考查定语从句，代词them指代disorders，故选C。