John joined the army three years ago.(用since或for改写） 怎么写.

John joined the army two years ago等于___two years since he joined the army joined the army什么意思? John joined the army three years ago.(用since或for改写） 怎么写. John joined the army two years ago.等于John_______for two years he joined the army last year It is 3 years_____he joined the army. my mother joined the army last years 同义句 he joined the army last year 改成现在完成时 He is a ____ .He joined the army last year. he joined the army last year 改成现在完成时 joined the army 这句话的汉语是什么? It is said _______ he has joined the army. Jack joined the army in 2006.(改为同义句)It ____ _____ three years _____ jack joined the army. his brother joined the army two year ago改同义句 空 two years 空 his brother joined the army He_____for twenty years.A.has joined B.has been in the army C.joined D.have saved the army James ( ) for three years.A.has joined the army.B.has been in army Hans ( ) the army for nearly six years.A.has joined B.has been in C.has joined in D.joined It is three years since he joined the army.为什么是用joined而不是用have joined