Вакуумная трубка повысила силу электрического сигнала. Поставить в формы Present simple ,Present Continuous,Past simple,Future simple,Present simple Passive voice
1)The vacuum tube raises the strength of the electrical signal. 2)The vacuum tube is raising the strength of the electrical signal. 3)The vacuum tube raised the strength of the electrical signal. 4)The vacuum tube will raise the strength of the electrical signal. 5)The strength of the electrical signal is raised by the vacuum tube.