全世界唯一的男人小说:高手帮帮忙

来源:百度文库 编辑:中科新闻网 时间:2024/07/06 17:39:49
12. He spent the whole morning _____ to solve the math problem.[ 1分]
A.to try B.trying C.having tried D.being tried

B
spend doing sth.