Accustomed to the steep mountain, he had no difficulty reaching the top.
A. climbing
B. climb
C. having climbed
D. have climbed
网友回答
(答案→)A. climbing
B. climb
C. having climbed
D. have climbed
解析：固定句型bee/be accustomed to doing sth.习惯于做某事。故选A. 这不选C或D。因为此处不存在先后关系一说，having done 一般非谓语动词连用，这里不能与宾语climbing连用。