Which of the following are changes to the environment which can lead to the spread of infectious diseases?
1.) soil erosion
2.) habitat destruction
3.) creation of irrigation canals and dams
4.) all of the above

the  frequency of a wave represents  the number of wavelengths that pass a specific point per second. the unit for  frequency  is hertz (hz).

happy to

pls mark as brainliest

sorry to break it to ya but no one can answer your question it's just

jk but i am serious about the part that most people cant answer it beacuse you did not mention the section you are talking about. but it would if you added some detail and were a bit more specific.