my guess is B. I am probably wrong
the respiration in human start from breathing.the oxygen is inhale and passes through larynx and reaches upto trachea and it goes in the bronchus.it is also divided into bronchoioles. it leads into lung
the bronchoioles that enter in the lung lead to small air sac called alveoli and it exchange gases and here exchange of gas occur and carbon dioxide is transported back to nostril through same passage and the canbondioxie is exhaled.in this way the process of respiration is completed
hope this helped..
Smallpox- began Africa, spread through trade and human interaction.
Chestnut blight-isn't this a chestnut found in America?
I think its A but I'm not sure.
The effect of such toxic chemicals to the body is that they stimulate uncontrolled cell division. Uncontrolled cell division or cells proliferation may lead to cancer. The unchecked cell growth results to mutations in genes that can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death.
