Прочитайте текст и определите, какой из заголовков соответствует тексту
An electric current is a flow of electricity. There are two kinds of electricity, positive and negative. Glass rubbed with silk is positively charged, ebonite rubbed with fur is negatively charged.
Like charges repel, unlike charges attract. The leaf electroscope is used to detect, distinguish and measure charges.
The ultimate particle of negative electricity is called the electron; that of positive is called the proton.