input: OPTIONS:
- chewing tobacco
- heredity
- tuberculosis
- tobacco smoke Now, answer this question: Answer the following question given this paragraph: Tobacco smoke contains dozens of carcinogens, including nicotine and formaldehyde. Exposure to tobacco smoke is the leading cause of lung cancer. Q: What is the leading cause of lung cancer? A:
A:
output: tobacco smoke

Answer the following question given this paragraph: Q: What is a primary source of the hormone melatonin? A:

OPTIONS:
- thymus
- pituitary gland
- thyroid gland
- pineal gland

Answer: pineal gland

Problem: OPTIONS:
- methane
- carbon dioxide
- nitrogen
- oxygen
Q: Answer the following question given this paragraph: Figure 39.19 The protein inside (a) red blood cells that carries oxygen to cells and carbon dioxide to the lungs is (b) hemoglobin. Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen. It is the iron in hemoglobin that gives blood its red color. Q: What does hemoglobin in blood carry to the cells? A:
Answer: oxygen

Problem:OPTIONS:
- habitat
- population
- biodiversity
- ecosystem

Answer the following question given this paragraph: Q: The community of all of the living and nonliving parts of an environment is known as what? A:
****
A: ecosystem

Answer the following question given this paragraph: Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. Q: Changes of state of matter do not involve what type of reaction? A:
OPTIONS:
- gaseous reaction
- radiation
- mechanical reaction
- chemical reaction
chemical reaction

Answer the following question given this paragraph: The blades of simple leaves are not divided. This provides the maximum surface area for collecting sunlight. Q: What is the limiting factor for bacteria in a dish? A:
OPTIONS:
- density
- speed
- material
- space

Answer:
space