1.With non-changeover control both the boiler plant and the chiller plant operate to provide simultaneous heating and cooling throughout the year. 采用非转换控制，锅炉设备和制冷装置都在运行，全年可同时供暖和制冷。 2.The online service delivers substantially more value to our global audience of e-business professionals in the chemical, plastics and allied industries. 该网络服务主要向全球从事化学，塑料以及相关工业的专业电子商务用户提供更有价值的服务。 3.This device can mimic photosynthesis to produce usable energy from sunlight. 这种设备可以模拟光合作用，利用阳光产生可用的能源。 某些介词可以转化为汉语的连词 1.With all its advantages, the accuracy of the new dating method using radioactiveC-14 can't be blindly trusted. 利用放射性C-14测定年代的新方法虽然有种种优点，但我们不可盲目相信其准确性。 2.For a polymer to be electrically conductive, it must“imitate” a metal—— the electrons in the bonds must be freely mobile and not bound fast to the atoms. 如果一个聚合物要导电，就必须像金属那样， 成键原子就必须能够自由移动，而不是与成键原子紧密结合。