He joined the ylounteers from all over the country请帮我翻译出这句话!

he joined the army last year He is a ____ .He joined the army last year. John joined the army two years ago等于___two years since he joined the army It is three years since he joined the army.为什么是用joined而不是用have joined He ________ the army for ten years.A.has joined B.has joined in C.joined D.has been in He joined the football club 为什么加the he joined the volunteers from all over the country是什么意思 EG：He ___ the club last month.A:joined B:joined in He the singing competitionlast year.(took part in ,joined in;joined)怎么区分 he joined the army last year 改成现在完成时 he joined the army last year 改成现在完成时 Elias trusted Mandela and he joined the ANC Youth League. He joined the party in 1999.(同义句转换） It is said _______ he has joined the army. 为什么joined?they said he would go to college if he (joined) the basketball club翻译并解释为什么用joined?they said he would go to college if he（ joined） the basketball clubjoin为什么加ed My uncle __the Party in 1978.He for over 19 years.a joined;has been a Party member b.joined;has joined the Party c.has joined;has been the Party d.has joined;has been in the Party He ( ) the army when he was eighteen years old.A.took part in B.joined C.attended D.joined in he joined the league in 2002改写he()()a()()the()for two years