是by ourself还是by ourselves?

是by ourself还是by ourselves? do the work是加ourself还是by ourself,为什么? by 是by boat 还是by a boat the future is ours to build by Reagan的原文 用 we us our ours ourself 造一句话 we enjoyed()last month.A;ourself B;ours C;ourselves 是by last term还是 by the last term 是Time gose by还是Time go by…… “时光飞逝”是time went by 还是 time goes by? 英语 ：通过旅游是用by travel 还是by travelling? 这句英文语法对吗But we do the mechanical engineering including reverse engineering and inspection by ourself. 这句英文 语法对吗But we do the mechanical engineering including reverse engineering and inspection by ourself. 这句语法对吗But we do the mechanical engineering including reverse engineering and inspection by ourself. The way we follow is chose by ourself. Sometimes memory is most beautiful. 有语法错误吗?路是自己走的...也许某些回忆是最美的.. 翻译英文是什么?.. 是with hand 还是by hand? 是use escalator 还是 by escalator passer-by是可数还是不可数? 是rise 4%,还是rise by 4%