D. Watershed - a watershed is the area in which runoff, rivers, and streams run into a larger body of water
Answer:
Part 1:
The four astronomical bodies one could choose to represent the 4 labels in the diagram are
A - universe
B - galaxy
C - solar system
D - Mars
The universe contains galaxies and galaxies holds solar systems which have planets like Mars
Part 2: D or a planet like Mars is unlike all their other astronomical bodies it does not have other astronomical bodies within it thus, its different from rest.
Transmitted, vertical
A transparent specimen is viewed through a microscope using transmitted light while an opaque object requires vertical illumination.
Transmitted light is the light that passes through an object. Transmitted light microscopy is any kind of microscopy in which the light is transmitted from a source located directly across the specimen from the objective. The light is commonly passed through a condenser in order to focus it on the specimen to obtain very high illumination. After the light passes through the specimen, the image of the specimen moves through the objective lens and later to the oculars where the enlarged image is viewed.
Im not for sure but i think its D if that helps any