二环的英文：
bicyclo
Bridged bicyclooctanes gave no significant bridgehead substitution
桥二环辛烷不给出有意义的桥头取代。
Half of the Erhuang Road are hot islands; experts suggest cooling.
北京二环内一半是热岛专家提出冷却建议
Adamantane and bicyclo (222) octane are predominantly Chlorinated at the bridgeheads by this procedure
金刚烷和二环〔222〕辛烷主要是按照这个程序在桥头氯化。
n.二环
Adamantane and bicyclo (222) octane are predominantly Chlorinated at the bridgeheads by this procedure
金刚烷和二环〔222〕辛烷主要是按照这个程序在桥头氯化。