My tireless little cilia make about ten sweeping strokes a second.我那不怕疲劳的小纤毛每秒钟约做10次清扫动作.Healthy, skin, mucous membranes, and cilia are natural barriers to many viruses.健康的皮肤, 粘膜和纤毛是许多病毒的天然屏障.Epithelium can also bear cil...
...a walk along the ramparts of the Old City.沿着老城的城墙漫步A number of staircases ascend from the cobbled streets onto the ramparts.一段石阶从鹅卵石路上一直向上直通城墙。Blocks of flats have been holed and some shells have fallen within the his...