他看到当地居民患病，就在一座高山上建造了梯子和房屋，用来储存数百种药用植物。

Seeing that local people were suffering from disease, he built ladders and houses on a high mountain to store hundreds of medical plants.

youdao

约翰把注意力转向了梯子上。

John turned his attention to the ladder.

youdao

有人正在画一个店面，因此出现了梯子。

Someone was painting a shop front, so there was a ladder.

youdao

It's the phosphate and the pentose that make up the backbone - that make up the upright struts of the ladder and it's the bases that make up the connecting struts, so the bases are the colors.

磷酸基和戊糖,共同构成了主链,主链又构成了梯子上下的支柱,而碱基,则构成连接支柱的梯阶,碱基是用各种颜色表示的

耶鲁公开课 - 生物医学工程探索课程节选