The circulatory system of ray-finned fishes has _______ circuit(s), and carries ________________ blood through the heart and ___________________ blood away from the gills. 

Why is the physical altercation with Mr. Covey a turning point in Frederick Douglass’s life?

This diagram shows a simplified illustration of the vertebrate heart and major circulatory structures. Match the letter in the label to the correct structure.   

Who first teaches Frederick Douglass the basic skills of spelling and reading?

The libertarian theory of justice is a doctrine holding that justice requires equal distributions of goods and social benefits among all persons.

Which is NOT a correct association of mammalian glands and functions? 

The circulatory system of ray-finned fishes has _______ circuit(s), and carries ________________ blood through the heart and ___________________ blood away from the gills. 

All of the following characteristics require amphibians to live in moist environments near water except

Plato made the argument that which type of relationship was superior:

Which of the following are endothermic? Choose all that are correct. (Partial credit is given; points will be removed for incorrect answers.)