Question: how were the rovers created

Hayley and the Mars Rover answered on 2 Dec 2020:

The rovers were created by lots of people that work for lots of different space agencies all around the world. Lots of people with lots of different jobs (scientists, engineers, technicians, designers) all worked together to make the best rover possible, that had all of the scientific instruments needed to answer their questions about Mars!
It took years to build the rovers and they had to be very thoroughly tested before they were sent to make sure everything would work when they got to Mars!