How many years does it take a star with the mass of the sun to convert all the hydrogen in its core

Dwarf galaxies are select one: a. relatively rare. b. not very bright c. mostly spiral shaped. d. none of these.

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Which of the following options describes photosynthesis correctly? question 8 options: a plant uses carbon dioxide and water to make oxygen and nitrogen a plant breaks down sugar to make carbon dioxide. a plant uses sunlight, carbon dioxide, and water to make sugar and oxygen. a plant uses sunlight to break down sugars for digestion into water and oxygen.