单选题 Many theories have been ______ as to why some women suffer from depression.
【正确答案】 B
【答案解析】(put forward提出)。句意为：就一些女人为什么患抑郁症而言，已经提出许多理论。A．refer to谈到，提及，查阅；C．rest assured放心；D．leave out省略，遗漏。