Answer;
C. Poor farming techniques that killed the soil were combined with drought.
Explanation;
-The Dust Bowl was caused by several economic and agricultural factors, including federal land policies, changes in regional weather, farm economics and other cultural factors.
-After the Civil War, a series of federal land acts coaxed pioneers westward by incentivizing farming in the Great Plains.
10 is 4
11 is 3
15 is 3 (where it says 3 ok)
Answer:
provide a large surface area of moist, selectively permeable membrane.
Explanation:
Answer:
A) & B)
Explanation:
A) There are certain viruses that are present in both healthy and disease people.
Example: Polio virus is found in many human but it causes disesease in only 1% of human.
B) Viruses require host machinery for replication so they may not replicate in pure culture.
The postulate C is also violated, the virus may not produce disease in non-human experimental host because of inappropriate animal or vaccinated animal etc. Others exception includes, the same disease may be caused by various organisms and different organisms can also cause the same disease.
Answer:
The theory of plate tectonics states that the Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet.
