Cindy shut the door heavily and burst into tears. No one in the office knew she

Cindy shut the door heavily and burst into tears. No one in the office knew ______ she was so angry.（ ）

A. where B. whether C. that D. why 　

试题答案

D

该空引导宾语从句，根据句意“办公室中没人知道她为什么如此生气”可判断选D项。