His explanation for what he called his "irrational and indefensible and inexcusable and inexplicable" behaviour was that he was disorientated after the crash.
2
没有连贯性或目的性的行为会让对方不知所措,为了试图解释你的行为而精疲力尽。
Behavior that seems to have no consistency or purpose will keep them off-balance, and they will wear themselves out trying to explain your moves.
3
虽然癌症过去100年中已经被诊断,但是内科医生不知所措解释疾病的下列原因。
Although cancers have been diagnosed for the past 100 years, physicians were at a loss to explain the underlying causes of the disease.