His friends did ____ they could ____him out of difficulty.A.all what; to help B.all; to help
问题描述:
His friends did ____ they could ____him out of difficulty.A.all what; to help B.all; to help
same rule,please give your answer and explain why.thanks :D
答
B
定语从句的先行词是all时,引导词用that,排除A