What is the difference between bicuspid valve and tricuspid valve?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

Why are some people more concerned about shark survival than about shark attacks?

Earthquakes a.created the rock in arches utah b.can be caused by volcanic eruptions c.are caused by tsunami waves d.wear mountains down into hills