a face mask的用法和样例：
- Members of the public may wear a face mask for self protection.
- I donned a face mask and jumped in the pool to watch Ris swimming toward me.
- Victor: Sure! By the way, don't forget to wear a face mask to English class.
- If you have to clean the cat's litter box, wear gloves and a face mask.
- Those patients should be given a face mask to wear, preferably one that provides filtration of their expired air.
- People with respiratory tract infections, or those caring for them, should wear a face mask.
a face mask的相关资料：