Bcf
[医][=bacterial chemotactic factor]细菌趋化性因子
🗣️ 情景例句
If you're under twenty-one years of age ...
如果你还不到二十一岁……
Kill two birds with one stone.
一石双鸟；一箭双雕。
We also played games on the sand.
我们还在沙滩上做游戏呢。