Polyacetals
聚缩醛(树脂)
🗣️ 情景例句
Or at least give him some advice.
再不然至少可以给他一些忠告。
Just a minute, please.
请等一下。
A week before, he had completed a successful overland flight during which he covered twenty-six miles.
一周以前，他曾成功地进行了一次26英里的陆上飞行。