My brother college for over three years.为什么用括号中的.有这种用法吗?

My brother college for over three years.为什么用括号中的.有这种用法吗? My brother ___ college for over three years. my brother has been ( ) college for over three years . My brother ____ college for over three years. A. has gone to spend three hours over lunch有这种用法吗 My brother has joined the army for three years.(同义句改写) My elder brother _____ the army for three years A.has joined my brother _____ the army for two years.用哪个选择是对的?为什么? i'm three years -______(young) than my brother,讲讲为什么? for twenty-five years和for over twenty-five years在时态用法上一样吗 My brother __the army for thress years. My brother (has) three为什么要用has