First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.
it just as it is tempting to take natural selection to extreme so no not all
I think that it is A. it forms new mountains under the water
Definitely 4 Play control environment temperature
Answer:
Mar 4, 2011 — Past changes in Earth's temperature happened very slowly, over ... Human activities contribute to global warming by increasing the greenhouse effect. ... Emissions of carbon dioxide, the most important greenhouse gas, ... Even slight rises in average global temperatures can have huge effects. ... 100 years.
Explanation: