He was seriously injured．He lay on the ground, to stand up．
A. was unable
B. being not able
C. unable
D. being able not
网友回答
A. was unable
B. being not able
(答案→)C. unable
D. being able not
解析：考查形容词用法。本题的形容词短语unable to do stand up是对主语he的情况进行说明。因为两个部分之间没有连词，说明后面不是完整的句子。故排除A项。Able的否定词就是unable.句意：他受了重伤。躺在地上，不能站起来。故C正确。