Thiết bị nào sau đây không phải là nguồn điện A. Ắc quy
B. Pin
C. Máy phát điện
D. Bóng đèn điện

Which best describes how fluids change as they travel through different portions of the convection currents? they change to solids at the outer portion of the convection currents. they change to solids at the inner portion of the convection currents. they become more dense at the outer portion of the convection currents. they become more dense at the inner portion of the convection currents

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false

Which system of units is used by only a small number of countries in the world, including the u.s.