Describe how sonar technology involves electromagnetic or sound waves.

Lol, sonar technology sends sound waves into the ocean and when the waves hit something, the device measures how long it took to hit something and come back basically

um i dont know

Explanation:

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.