2.句义的把握 An understanding of the sources,effects. measurements,and uses of electricity and magnetism is valuable to the worker in that it enables him to use more effectively the manifold electrical devices now so vital to our efficiency in work. 搞懂电和磁的来源、效应、测量方法及其用途，对 于操作工是很有价值的；有了这些知识就能使他 们提高工作效率，得心应手地操作各种电气设备。 这对我们工作的效率是至关重要的。 2. 句义的把握 An understanding of the sources, effects, measurements, and uses of electricity and magnetism is valuable to the worker in that it enables him to use more effectively the manifold electrical devices now so vital to our efficiency in work. 搞懂电和磁的来源、效应、测量方法及其用途，对 于操作工是很有价值的；有了这些知识就能使他 们提高工作效率，得心应手地操作各种电气设备。 这对我们工作的效率是至关重要的