The ability to study chemical reactions stage by stage will be equally important.

能够研究化学反应中的每一步同样很重要。

And in this way, complexity builds stage by stage.

通过这种方式，复杂性会逐步增加。

Stage by stage, he lost his strength, until he couldn't help squalling.

逐步地，他失去了气力，直到他禁不住嚎啕起来。

Julien was too faithful to what he called his duty to fail to accomplish stage by stage what he had mapped out for himself.

于连对他所谓的职责过于忠诚，以至于无法逐步完成他为自己制定的计划。