Astronauts in space need to communicate with each other by radio links because

User login

3 + 1 =
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.

Astronauts in space need to communicate with each other by radio links because:

sound waves travel very fast in space

sound waves travel very slowly in space

sound waves cannot travel in space

sound waves have low frequency in space