|Human cells organize into ____ and then into organs.
|The reproduction of bacteria can be inhibited by ____.
|Hypersensitivity of the immune system can cause ____.
|The inner wall of the small intestine is covered with ____.
|Inhaled asbestos and tobacco smoke are non-radioactive ____.
|Your two ____ take in oxygen and expel carbon dioxide.
|Humans have 20 primary and 32 permanent ____.
|The brain, heart, stomach, and lungs are examples of ____.