wǒ / dì / yī / cì / qù / měi / guó / shí / céng / zài / ào / kè / lā / hé / mǎ / tíng / liú / le / jǐ / tiān

我第一次去美国时，曾在奥克拉荷马停留了几天。

When I first went to the United States, I stayed in Oklahoma for a few days.