Epidemiological
a. 流行病学
✅ 同义词
🗣️ 情景例句
Do you have any coupons?
你们有优惠卡吗？
I asked him to lend me a book , but he wouldn't.
我请他把书借给我，但是他不肯。
I want some envelopes,please.
请给我拿几个信封。