What did the clean air act of 1970 permit u. s. citizens to do for the first time?

a.
participate in the environmental movement in other nations
b.
influence local environmental laws
c.
sue polluters for violations
d.
join together for mass rallies and protests

What is the next step in muscle contraction after the actin changes shape? (apex)

1. seamount a raised footwall block between normal fault creates this 2. syncline break between rocks where a hanging wall rises relative to a footwall 3. hot spring on rolling hills, this a dip between hills 4. volcanic neck created when a block with hanging walls slips down between normal faults 5. caldera underwater volcano that never reaches above sea level 6. horst natural hot water on earth's surface containing many minerals 7. graben underwater volcano whose top is eroded flat by waves 8. crater less than a mile in diameter; looks like a bowl at the top of a volcano 9. guyot magma that filled the central vent that remains after the volcano has eroded 10. reverse fault over 1 mile in diameter; looks like a bowl over a volcano

What are positive impacts of algae? how is it used?