三角形按边分为等边三角形和锐角三角形。（ ）
下列各句中，标点符号使用正确的一项是( )
- I bought Collecting the Morning Flowers in the Evening, a book written by Lu Xun. Would you like to read __________?
- No, thanks. I have already bought __________.
— Tom, who taught Chinese before you came to China?— Nobody. I learned it by .
