Chemex
化学交换(同位素浓缩)过程
🗣️ 情景例句
It's easy to pick something for my colleagues, but it's difficult for my boss.
给同事们的应该不难买，但是给老板的就难罗。
Kill two birds with one stone.
一举两得。
Grandma is ill, she said. I must take her to hospital.
“奶奶病了，”她说，“我必须送她去医院。