Answer:
ugh i wish I knew it its number 19 for my exam on flvs
Explanation:
B) Determining the absolute ages of the rock
The ratio of 
indicates the purity of nucleic acid.For pure DNA it should lie between 1.8-2.0.Whereas for RNA it should be greater than 2.
This is calculated for DNA using the given values of absorbance-
= 2.71
As the value is greater than 2.0,it reflects the RNA contamination in the sample.
The correct answer is C. it takes up space and has mass.
This is something which is true of all matter. A is incorrect because it can be made of other things as well. B is incorrect because it can be found elsewhere as well. D is incorrect because it can take any form it wants - not just liquid or gas.
<span>Models are very helpful, but they also have limitations.Details - Models cannot include all the details of the objects that they represent. For example, maps cannot include all the details of the features of the earth such as mountains, valleys, etc.Approximations - Most models include some approximations as a convenient way to describe something that happens in nature. These approximations are not exact, so predictions based on them tend to be a little bit different from what you actually observe. Models do not behave exactly like the things they represent.Accuracy - In order to make models simplistic enough to communicate ideas, some accuracy is lost. For example, ball and stick models of atoms do not show all the details that scientists know about the structure of the atom.</span>
