What structure is composed of two layers of fat molecules that are free to flow around one another?

According to research by de Haan & Johnson, increasing cognitive complexity is due to

transient exuberance. synaptic regeneration. axonal pruning. synaptic pruning.

Sometimes human development research involves deception. What do the ethical guidelines require?

a. explain the research to the participants after the study has been completed b. avoid the manipulation of variables in research involving human subjects c. forewarn the participants about exactly what will happen to them during the study d. avoid the use of monetary incentives