问题
选择题
I don’t know _____.
A．what happened to him
B．what did he happen
C．what he happened
D．what was the matter
答案
答案：A
考查宾语从句。特殊疑问句做宾语时，应用陈述句语序，可排除A，D选项语序不变，但是时态应用一般现在时态。what happened to sb，表示某人怎么了，句意：我不知道他怎么了。故选A