I bought a new bike just now.(用just改写）

I bought a new bike just now.(用just改写）
I bought a new bike just now.(用just改写）

I bought a new bike just now.(用just改写）
答案是：用just 改写就要改变时态为现在完成时 I have just bought a new bike 尊重劳动,欢迎提问,