Operational research
出国 Abroad[经] 运筹学
🧩 词语组成解析
research
['risɝtʃ]
n. 研究，追究;探讨，探测;调查;探索;
vi. 做研究;探究;（从市场调研中）得出所预测的结果;
vt. 从事…的研究，为…而做研究;
re(again)+search(to go round)→研究；调查
🗣️ 情景例句
Where is your family from?
祖籍在哪里？
He was absent yesterday. Do you know why?
昨天他没到，你知道为什么吗？
Thank you .It was very nice of you to help me.
谢谢你帮我，你真好。