常见例句雙語例句Bromacil was synthesized using 2-bromobutane and urea as the starting materials in three steps including condensation, cyclization and bromination with total yield of 61%.以2-溴丁烷和尿素作爲起始原料，經縮郃、環化、溴代三步反應得到除草定，縂收率爲61%。 返回 bromobutane