英语语法分析

Toothpastes and mouthwashes are good sources of fluoride.

牙膏和漱口水是氟的良好来源。

He often hawked toothpastes in the street during the vacations.

上大学期间每逢放假，他便在大街上沿街兜售牙膏。

Toothpastes that promise whitening or gum health are another.

美白功能的牙膏和保健口香糖是另外的反例。