帶口罩是要提倡的。至少可以降低進入口鼻的病毒的濃度。

來源: gweipwu 於 2020-08-01 21:12:06 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.