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.
All of the above, here's an explanation. The sun helps the water cycle due to evaporation which causes it to turn into a steam/gas. Now for wind, it's because the sun heats up the air and causes thermal energy which later turns into wind. And finally, weather, obviously the sun evaporates water which causes it to be rainy/drowsy.
Answer:
C
Explanation:
It is known as lactation. The suckling action of an infant produces prolactin, which leads to milk production; more suckling leads to more prolactin, which in turn leads to more lactation. This is a positive feedback system as the product (milk) produces more suckling and more hormone. When the child is no longer breast feeding, the prolactin drops off and milk production goes down.
The intervertebral discs, which are between vertebrae, are the parts that prevent the vertebrae from grinding against one another.
The intervertebrals discs act as a cushion; they absorb the stress and shockw that occur during movement, preventing such grinding.
The answer would be analogous and convergent evolution. In evolutionary biology, convergent evolution is the procedure whereby creatures not carefully related, self-sufficiently evolve alike traits as an outcome of taking to familiarize to like surroundings. The beaks can be described as analogous since there is a similarity of structures that came from different origins.
