We gain energy from eating plants. plants can't create their energy; they must first get it from the sun.

this statement is according to the law of thermodynamics.

true; first

true; second

false; first

false; second

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed

Forensic scientists think they know the identity of a skeleton. what rule should they use to select a relative whose dna could be used to try to confirm the identity?

According to the article, what valid claim came from the national research council? there is no association between fluoride exposure and increased cancer risk in humans. there is a possible link between fluoride exposure and increased cancer risk in humans. there is a definite link between fluoride exposure and increased cancer risk in humans.