What does a phospholipid contain

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?