Tracerlab
同位素示踪物实验室
🗣️ 情景例句
I can't.
我不敢读。
One may sooner fall than rise.
跌倒容易爬起难。
Notices forbidding the open-air drying of clothes, or the use of water points for car washing,
禁止露天晒衣服、禁止用水龙头冲洗汽车的布告