Difference operator
[计] 差分算子
🧩 词语组成解析
🗣️ 情景例句
If you find it unworkable, we have no other choice but to call the deal off.
如果不行的话，我们只好放弃了。
To drop
掉下
The question became one of whether Man could control the disease he had invented.
现在的问题是，人类能否控制住这种人为的疾病。