Which of the following describes what happens as oil is used in an engine? It picks up dirt.
It moves to the top of the crankcase.
It increases friction.
O It produces carbon buildup.

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.