Pcas
(pca 的复数) abbr. 污染控制局（Pollution Control Agency）；极地冷空气堆吸收, 极冠吸收（Polar Cap Absorption）；波特兰水泥协会（Portland Cement Association）
🗣️ 情景例句
What do you do in your spare time?
你在业余时间做什么？
Would he have seen you if you hadn't waved to him?
如果你没向他招手他会看见你吗？
OK. Let me help you. There!
好，让我来帮你。