You are presented with the quiz "what has a positive impact on the environment?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "recycling has a positive impact on the environment" and "recycling means reusing things". So, what's the best answer to the question?
OPT:
I. temperature
II. reusing things
III. a hydraulic system
IV. water conservation
V. peachleaf willow
VI. density
VII. Green beans
VIII. addition
II.