Betti number
[计] 贝蒂数
🧩 词语组成解析
[计] 贝蒂
🗣️ 情景例句
is no longer in service.
是空号。
She sent me a Christmas card last year.
去年寄过一张圣诞卡。
Oh ,dear! she said.
“天哪！”她说。