Why do geologists think Earth's core contains mostly iron? A. The crust also contains mostly iron.
B. The entire core is a solid mass.
C. Iron is the lightest element.
D. Comets contain more iron than Earth's crust does.

Which statement best explains why cells were observed in more detail using a compound microscope than a simple microscope? a compound microscope has greater magnification ability than a simple microscope. the compound microscope was invented before the simple microscope. a compound microscope is much easier to manufacture than a simple microscope. compound microscopes were more common than simple microscopes.