<span>The purpose is to prevent going into the negative zone. When you start paying with checks and you don't have money on your account that's the same as stealing things which means that you can get arrested for paying with checks while not having money. It's like fraud. Also, in case you're late with payments, you can get interest rates that don't suit you.</span>
They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe.
If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
So the answer for (a) is basically the enzyme is breaking down the protein (which is the colored part) and this leaves the clear.
For the constants it would be the film and the temperature that the solution is at
For the final question, they could be improved by using more data and multiple trials
The Nile does not run there