Prehnitene
[化] 连四甲苯; 1,2,3,4-四甲基苯
🗣️ 情景例句
my friends,
我的朋友们。
It's a sunny day.
今天是个艳阳天。
Many firms, for instance, have great difficulty in obtaining technical or scientific books from libraries
比如，很多公司向图书馆借阅科技书籍时感到很困难，