R factors
[医] R因子, 叶酸
🧩 词语组成解析
n. 因素（factor的复数）
🗣️ 情景例句
Certainly. Do you have any identification?
当然可以。你有任何证明文件吗？
I have received a letter from my cousin.
我收到了我表兄的信。
We had to queue for hours to get in and there must have been several hundred people present just before the show began.
我们不得不排了好几个小时才进得场去。在演出开始前场内肯定已有好几百人了。