Waterfall model
[计] 瀑布模型
🧩 词语组成解析
🗣️ 情景例句
What happened?
怎么啦？
This is our common desire.
这是我们的共同愿望。
She does, doesn't she! I read she's twenty-nine,- but she must be at least forty.
是的，谁说不是呢！我从报上看到她是29岁，但她一定至少有40岁了。