问题补充：
The old man had one son and two daughters, treated him well, made him very sad.
A. neither of whom; that
B. neither of them; which
C. none of whom; which
D. none of them; which
答案：
A. neither of whom; that
B. neither of them; which
(答案→)C. none of whom; which
D. none of them; which
解析：考查定语从句：第一空填none of whom，因为先行词是one son and two daughters,三者以上，用none，因为是定语从句，用none of whom，第二空填which，指代前面的句子，句意：老人有一个儿子和两个女儿，没有人对他好的，这使他很难过。选C。
