这就像是一种化学试剂.It is like a chemical reagent.这种双用试剂把蛋白质分子彼此连接起来.This bifunctional reagent links protein molecules to one another.碳容易被亲核试剂进攻.The carbon should be susceptible to attack by a nucleophilic species....
Was she going to act and keep house?难道她要一边演出一边持家 吗 ?His mother helped to keep house for him.他妈妈帮助他管家.Since their mother died my sister often helps them to keep house.由于他们的妈妈去世了,我姐姐经常帮助他们料理家务....
AB线是三角形abc的底边.Line AB is the base of the triangle ABC.这个三角形,底边的长度是20厘米.The base line of this triangle is 20 centimeters long.这三角形的底边与这四边形的一边相重合.The base of the triangle coincides with one side of the square....