Because Evolution, theory in biology postulating that the various types of plants, animals, and other living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations
Advances in science and technology can be affected by a number of factors such as:
<span>1) the values and attitudes of people within a society
2) the cultural backgrounds of scientists and engineers
3) the technological limitations of a society
4) the social and economic needs of a society</span>
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. hope this helps :)