Q: At how many places does points source pollution enter water? Choices: - three - two - four - one A:
one

Q: What type of change has occurred when a copper penny changes color? Choices: - contamination change - carbon change - reactive change - chemical change A:
chemical change

Q: What man-made substance tends to break down ozone in the stratosphere? Choices: - gasoline - steel - plastic - cfcs A:
cfcs