Which compound was abundant in Precambrian Earth's oceans, before complex life evolved on Earth?

A.

dissolved oxygen

B.

dissolved carbon dioxide

C.

dissolved methane

D.

dissolved ammonia

A metal sphere rests upon the exact center of a level, square tabletop. The table is sitting on the floor. Andrea knows the mass of the sphere; what other measurement does she need to calculate the potential energy of the sphere?

What is the correct term for a source of historical climate data?

A geologist finds a metamorphic rock and notices that it has grains that formed in parallel layers. The geologist pries at the rock, and it splits apart along the bands formed by the layers.

Why do some scientists believe that carbon dioxide is responsible for global warming? Check all that apply. Carbon dioxide levels in the Earth's atmosphere have been steadily decreasing.

Which type of infection does not have a medicinal treatment? A. viral B. fungal C. protistan D. bacterial

How are mosses and horsetails similar to ferns

Determine approximately how much total energy is lost from a three step food chain if 1000 calories enter at the autotroph level

Give two examples of equations for the synthesis of transuranium elements by transmutation

In muscle the source of a "phosphate molecule needed to recharge an adp molecule to an atp molecule" is

5. What would occur if ... a ... the wildflower population decreased?