The strings are now metallic but sixteenth, seventeenth to eighteenth century they would have been made out of cat or sheep gut.

弦现在是金属的,但在十六,十七,到十八世纪,弦是用猫肠或羊肠线制作的

耶鲁公开课 - 聆听音乐课程节选

In order for it to get inside the cells and go through them there have to be transporters which specifically allow glucose to pass into the cell and then out into our body.

为使其能进入并穿过细胞,肠上皮必须具有葡萄糖特异性的转运蛋白,使葡萄糖能够穿过细胞进入体内

耶鲁公开课 - 生物医学工程探索课程节选