He's stepped out of the office for a little while.
他离开办公室刚一会儿。
I'll have studied English for four years next March.
到明年三月,我就学了四年的英语了。[将来完成时,表示将完成…,会做完…]
and these will ply the short wings with such irresistible power that they can bore for long distances through an opposing gale before exhaustion follows.