input: OPTIONS:
- gravity
- uteris
- ovaries
- lack of fertilization Now, answer this question: Answer the following question given this paragraph: The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. It includes changes in the uterus as well as development of an egg and ovulation. If fertilization does not occur, menstruation occurs and the cycle repeats. Q: What causes the menstrual cycle to be repeated? A:
A:
output: lack of fertilization

Answer the following question given this paragraph: Under the direction of osteocytes, osteoblasts continuously build up bone, while osteoclasts continuously break down bone to maintain mineral homeostasis. Bone tissues include compact bone, spongy bone, bone marrow, and periosteum. Q: Osteoclasts break down bone to maintain mineral what? A:

OPTIONS:
- density
- fluctuations
- polarity
- homeostatis

Answer: homeostatis

Problem: OPTIONS:
- excretory
- respiratory
- neither
- both
Q: Answer the following question given this paragraph: The lungs release carbon dioxide into the air. Carbon dioxide is a gaseous waste product of the cells. Wastes are excreted from the body by the excretory system. Therefore, the lungs are organs of the excretory system as well as the respiratory system. Q: Are the lungs organs of the excretory system, the respiratory system, or both? A:
Answer: both

Problem:OPTIONS:
- fossil fuels
- oxygen
- greenhouse gas
- atmosphere

Answer the following question given this paragraph: We are lucky to have an atmosphere on Earth. The atmosphere supports life, and is also needed for the water cycle and weather. The gases of the atmosphere even allow us to hear. Q: What supports life, and is also needed for the water cycle and weather? A:
****
A: atmosphere

Answer the following question given this paragraph: A day or two after an ovary releases an egg, the egg may unite with a sperm. Sperm are deposited in the vagina during sexual intercourse. They propel themselves through the uterus and enter a fallopian tube . This is where fertilization usually takes place. Q: Where does fertilization usually take place? A:
OPTIONS:
- uterus
- ovary
- vagina
- fallopian tubes
fallopian tubes

Answer the following question given this paragraph: Macroevolution occurs over geologic time above the level of the species. The fossil record reflects this level of evolution. It results from microevolution taking place over many generations. Q: Microevolution occuring and taking place over many generations results in? A:
OPTIONS:
- fission
- microinjection
- recalibration
- macroevolution

Answer:
macroevolution