In addition to being necessary for respiration, also provides uv radiation protection.                a.  hydrogen      b.  carbon dioxide      c.  water      d.  oxygen

Plants that have reproductive structures called cones are?

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?

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.