Diacaustic
散焦面, 散焦曲线
🗣️ 情景例句
I got the first round.
第一轮我请的客。
Better ask twice than lose you way once.
宁愿问路两次胜过迷路一次。
but few us have had the opportunity to find out.
但很少有人能有机会去弄个究竟。