Serovar
血清变型
🗣️ 情景例句
Thanks again.
再次谢谢 。
He often fails to keep his word.
他常常不遵守诺言。
Looking at his watch, he saw that it was one o'clock, but the bell struck thirteen times before it stopped.
他一看表，才1点钟，可是那钟一边敲了13下才停。