Ballvalves
(ballvalve 的复数) 球型人造瓣膜
🗣️ 情景例句
This is Nat Baker,
这是Nat Baker
What channel are you watching now?
现在你在看哪个新闻？
A short while ago, my sister helped me to carry one of my old bookcases up the stairs.
几分钟前，我妹妹帮我把一个旧书橱抬上了楼。