Помогите пожалуйставыписать из текста эквиваленты к словам и словосочетаниям: поток

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выписать из текста эквиваленты к словам и словосочетаниям: поток электричества, трансформатор, постоянный ток, источник переменного напряжения, линия.
Текст
Current is a flow of electricity through a circuit. There are two main types of current: direct and alternating. A direct current flows a conducting circuit in one direction only. It flows provided a direсt voltage source is applied to the circuit.An alternating current that changes its direction of flow through a circuit.It flows provided an alternating voltage source is applied to the circuit. Alternating current flows in cycles. The number of cycles per second is called the frequency of the current.In a 60-cycle alternating current circuit the current flows in one direction 60 times and in the other direction 60 times per second. It is easy to transform a.c power from one voltage to another by a transformer. Transformers are also used to step down the voltage at the receiving point of the line to the low values that are necessary for use.When necessary a.c. can be changed into d.c. but this is seldom necessary.