They had been ( )about the origin of the universe for several hours without reaching a conclusion.
问题描述：
They had been ( )about the origin of the universe for several hours without reaching a conclusion.
They had been ( B )about the origin of the universe for several hours without reaching a conclusion.
B.debating D.discussing
为什么不选D,“讨论”不行吗?
答
debate争论 应该更符合句意