Which of these occurs in the first trimester of human pregnancy? A. The fetus accumulates fat under its skin.

B. The fetus's lungs become fully developed.

C. The fetus is able to move its limbs.

D. The fetus becomes medically viable.

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?

What is any method of measuring the age of an object or event in years, such as using atomic half-life?

What happens when a scientific theory is shown to be an accurate description of a phenomenon?