The answer is observations
If the inner lining of the air sacs neither thin nor highly vascularized, then it can be inferred that AIR SACS ARE CANNOT BE THE SITES OF GASEOUS EXCHANGE BETWEEN AIR AND BLOOD. Air sacs are generally lined with mucus and surrounded with blood capillaries.
In case of birds, air sacs play an important role in respiratory system.
Yes It's Possible for a curved path to move by force
True if u know that humans are
Answer:
b. the laboratory setting may not be a good representation of the real-world setting
Explanation:
The laboratory setting is different from the real world settings due to the real world settings having uncontrolled variables and conditions. Whereas the laboratory setting have controlled variables and conditions in which experiments could be performed under. The controlled or uncontrolled conditions could either influence the experiments positively or negatively.