Tbt
[建] 钛酸四丁酯
🗣️ 情景例句
The important thing is that you tried.
重要的是你已经努力过了。
I didn't know whether to send the letter airmail or not.
我不知道是否送航空邮件。
This is a good photograph.Who are these people?
这是一张很好的照片。这些人是谁。