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.
<span>The area of the brain responsible for memory (and, thus, also memory problems like amnesia) is a tiny area called the hippocampus. The hippocampus allows us to make short-term memories into long-term memories.</span>
Answer:
sunlight is the requirement of every single natural process on earth.
