He was known for his strength. Railroads began to link the United States together in the nineteenth century.

VOA: special.2009.02.21

So what's going to form the backbone is this continual link, phosphate to sugar, phosphate to sugar, phosphate to sugar, all linked together to form one long, long molecule.

主链是由这样重复的连接构成的,从磷酸到戊糖,周而复始,所有这些连接起来构成一个长链分子

耶鲁公开课 - 生物医学工程探索课程节选

So what's going to form the backbone is this continual link, phosphate to sugar, phosphate to sugar, phosphate to sugar, all linked together to form one long, long molecule.

主链是由这样重复的连接构成的,从磷酸到戊糖,周而复始,所有这些连接起来构成一个长链分子

耶鲁公开课 - 生物医学工程探索课程节选