The calculated results show that the aza Wittig reaction is a two step reaction, having one four membered ring intermediate on its reaction surface.

计算结果表明该反应是一个二步反应，在反应途径上存在一个四元环中间体。

youdao

On the surface, it appears that the reaction of the mob came in response to a video produced by an individual or group in the United States.

FORBES: Responses To The Attack In Libya: We Are Not In Elementary School

Even at its weakest, Microsoft Surface garnered twice as much positive social media reaction as negative.

FORBES: How Are Techies Reacting To A $499 Microsoft Surface?

People with celiac disease usually have a certain type of cell surface receptor that helps set off the immune reaction.

FORBES: Gluten-Free Diets: Miracle Or Hype?