问题
单项选择题
On hearing of the case some time later, Conan Doyle was convinced that the man was not guilty, and immediately went to work to ascertain the truth.
A. explore
B. obtain
C. verify
D. search
答案
参考答案：C
解析： 各项的意思是：explore探测，探究；obtain获得，得到；verify检验，查证；search搜索，调查。划线单词ascertain的意思是：确定，探知。句意是：听到这个案子一段时间之后，Conan Doyle确信这个男人是无罪的，便立即着手调查真相。所以，答案是C。