The body's first shield from foreign invaders is

In which state was more than 100 billion tons of coal mined in 2005?

What processes would you expect to be key in the production of yogurt ?

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?