Questions about science in the third grade of primary school

The sound of 1 is transmitted by waves and radiates in all directions.

Do not use inferior electrical appliances, and do not violate the safety operation rules when using them.

We are surrounded by the atmosphere, there is air, and sound can spread through the air.

Magnetic poles with the same name repel each other, with low noise, high speed, comfort and safety.

Noise is the sound that interferes with people's study, life and work. Harm is to affect people's physical and mental health and interfere with people's normal work, study and life.

Wet clothes are conductive, which can easily lead to electric shock accidents and may also damage wires.