D - In Experiment 2, chlorophyll level was tested in addition to phosphates and nitrates, while in Experiment 1, it was not.
Question NINE
C - Sample 4
Question NINETEEN
D - Test tube 5
Question THIRTY-TWO
H - direct
Question THIRTY-EIGHT
F - increases only
Question FOUR
Question TEN
H - larger than .06mm
Question TWENTY-ONE
D - All possible combinations of nutrients were not tested.
Question THIRTY-THREE
Question THIRTY-SIX
Question SIX
J - 20.1 mg / L
Question TWELVE
H - the same material that composes the terrestrial planets
Question TWENTY-SEVEN
D - II and IV only
Question THIRTY
H - Uniform particle size; low concentration of contaminants.
Question THIRTY-NINE
A - Hydrogen
Question THREE
C - increasing the number of farms on the lake.
Question FOURTEEN
G - The asteroids' ice content decreased after the belt was formed.
Question TWENTY-NINE
D - 20.9
F - Increasing over time
Question THIRTY-SEVEN
D - 16 psi / 150*C
Question FIVE
A - Sample groundwater near the sewage systems, testing for phosphate and nitrate content.
Question SEVENTEEN
C - 10,000:100:10
Question TWENTY-FOUR
F - Varying the amount of yeast added to the test tubes and repeating the steps of Experiment 3.
Question THIRTY-FIVE
A - A rock with a low density will always be highly porous.
Question FORTY
J - Fauna F