Tau.
[医] 寿命(放射性物质)
🗣️ 情景例句
Hi, girls.
嗨 ，女孩们好。
I do not know whether you realize it, but this condition is essential to us.
我不知道你是否了解，但是，这个条件对我们是必要的。
He says the Chinese people are very friendly.
他说中国人都很热情。