Plb
abbr. personal locator beacon 人员失事示位信标; plumber 水管工人; plumbing 铅工业; 铅管品制造
🗣️ 情景例句
What does that mean in plain English?
你能不能用大白话解释一下？
When one is about to act, one must reason first.
凡事要先思而后行。
when a significant number of people are living permanently in space.
如果有相当数量的人永久性地住在太空，