Answer:
New flu vaccines are released every year to keep up with rapidly adapting flu viruses. When you get vaccinated, your immune system produces antibodies to protect you from the viruses included in the vaccine. But antibody levels may decline over time — another reason to get a flu shot every year.
Explanation:
Weather patterns and soil conditions.
The DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones
1. The correct answer is B.
Blatantly increasing or decreasing the rate of transpiration is not an accurate way to measure the typical amount of water that is lost through transpiration, which eliminates choices C and D. The method proposed in choice B is pretty wrong and will lead to the collection of no water.
For the second question, the correct answer is A. The prompt mentioned that the dirt area contained the most water, which automatically eliminates choices B and D. What makes choice C wrong is that the water reached the materials in equal amounts, but some of them were able to infiltrate the water faster. Hard-packed dirt will, due to its thickness, always take the longest to infiltrate water.
For the third question, we know that energy is required to melt things -- thus eliminating choices B and D. Because the energy is being used, it would have to lose some energy and not gain any back unless you're melting something. The difference between choices A and C is that HEAT is released during crystallization...only! In order for something to melt, heat/energy must be taken in. So, the correct answer is C.
