We have already said a good deal about the various problems the war.
A. trying out
B. dating back to
C. appealing to
D. relating to
网友回答
A. trying out
B. dating back to
C. appealing to
(答案→)D. relating to
解析：短语辨析。A试验；B追溯到。C吸引；D与..有关；结合句意可知D正确。句意：我们已经说了一个和战争有关的很多的问题好的处理方法。