Where does the sugar we eat come from?
a) grassy sugar canes plants and sugar beets
b) sugar trees
c) it is minded from the earth
d)animals

Which of the four major uses is predicted to change the least by 2020?

Environmental differences within ecosystems are generally caused by

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy