根据英语翻译下面短语的意思并完成句子。

by chance _____    by accident ___by mistake _____          by luck___by design ___by good fortune___by necessity___I met an old friend of mine _____ in the street.

 我在街上偶然碰到了老朋友.

— How did you find your lost bike？

     你如何找到的你丢失的自行车？   — _____.      凑巧找到的.

I had no trouble passing on the driving test in the end ___.

    由于运气好最后我通过了驾照考试.

He has finished his task ahead of time______.

    由于进行了周密的筹划,他提前完成了任务.

The war will break out between the United Sates and Iran_____ in time.

    伊美之间迟早会不可避免地爆发战争.