Concentration gradiant
[电] 浓度梯度
🧩 词语组成解析
🗣️ 情景例句
Speaking of promoting the book,
说起促销书的事
I'm glad you helped me.
我很高兴你能帮我的忙。
'I found this outside this gentleman's room,' she said.
“这是我在这位先生的房门外捡到的，”她说。