Ppg
abbr. 聚丙二醇；脉冲程序发生器（ programme pulse generator）；每加仑脉冲数（Pulses Per Gallon）；聚醚
🗣️ 情景例句
For a beginner, you're pretty good.
做为一个初学者，你已经做得很好了。
A man becomes learned by asking questions.
要长学问，就得多问；多问则业精。
what would civilization be like without its benefits?
如果不受其惠，文明将会是个什么样子呢？