(i)what relationship seems to exist between the number of species of snail present and the concentration of calcium in the water?

(ii) Give a possible explanation for this relationship based on the fact that one of
the components of a snail's shell is calcium

If someone could do the first couple, just so i can see how it's done that would be great! 20 points. complete a dichotomous key for the 10 leaves on the common leaves sheet. the chart provided here allows for 11 pairs of statements. depending on how you build your dichotomous key, you may or may not need all of them, or you may need to add some.

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?

Need the diagram below, which is not drawn to scale, shows the position of the earth, moon, and sun. what type of eclipse occurs when the earth, moon, and sun are lined up in the order shown? a. planetary eclipse b. solar eclipse c. martian eclipse d. lunar eclipse