The betaine will collapse to the alkene only when these two functions are eclipsed.只有当这两个基团移至重迭位置时碘盐才能裂解为烯烃.The gramophone had been eclipsed by new technology such as the compact disc.激光唱片等新技术使留声机黯然失色。Our happiness was s...
Our happiness was soon eclipsed by the terrible news.我们的快乐很快就被可怕的消息蒙上一层阴影.The moon is partly eclipsed.月偏食了.The gramophone had been eclipsed by new technology such as the compact disc.激光唱片等新技术使留声机黯然失色。...