Disphenoid
复正方楔; 双半面晶形
🗣️ 情景例句
Your birthday is tomorrow, isn't it?
你明天生日 ，是吗？
He who makes no mistakes, makes nothing.
不犯错误，成不了事。
Sometimes the secrecy goes to such an extent that the whole nature of the research cannot be mentioned.
有时，保密竟达到了这样的程度，即连研究工作的整个性质都不准提及。