What is the length of time called that a product is usable and saleable?

All of the following are free tools to you prepare for the sat except

Remote sensing of the earth's surface and atmosphere may involve the use of what type of instruments?

These three organisms are interdependent on each other for their survival. what will happen if foxes are eliminated from the region? a. there will be more rabbits and less grass in the region. b. there will be more grass and fewer rabbits in the region. c. there will be fewer rabbits and less grass in the region. d. there will be more rabbits and more grass in the region.