Which structure is a specialized organ in which most mammals develop internally?
- Vagina
- Placenta
-Umbilical Cord
-Uterus

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.