Due to his leg injury, he has been discharged from the military for 9 years.
leg injury 腿伤, discharge from 从部队退伍, military 部队。
句子用了for 9 years (9年之长)而且他是被军队而退伍的, 所以句子用了现在完成时的被动语态。
he retired from the army 9 years for a leg injury
He retired in nine years because of a leg injury.
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