The correct answer is - D) covered by warm shallow seas.
The fact that the crinoids are have an abundance in the fossil records in Pennsylvania in the Mississippian Period, tells us that this area was covered with shallow and warm seas. The reason why we can get that conclusion is that the crinoids live only in that kind of environment, so it simply a logical conclusion.
The geological data is also confirming this, as it is easily noticeable in the layers that during this period of the geologic past, what is now Pennsylvania, was covered with shallow sea waters. Also, this waters were warm too, as the climate was warm and humid and that period, so it was a perfect environment for the crinoids to flourish.
Hypothesis is a proposed explanation which is made on the basis of given experimental data taken as starting point for further investigation. All hypothesis test are conducted in a same manner fiollowing the four main steps:
1. State the hypothesis
2. Formulate an analysis plan
3. Analyzing the data obtained
4. Final step is to analyze the results
There are three types of variables taken in an experiment:
1. Independent variable: light, temperature, humidity
2. Dependent Variable: these depends upon the other variable. changes in the independent variable may cause the dependent variable to change, for example, growth of plant is a dependent variable which depends upon the amount of light(independent variable), the plant receives
3. Controlled Variable: these variable can be controlled and prevented from being change like ty[pe of plant, type of soil
The answer is young child.
Nasal regurgitation it's when the food regurgitates out of the nose.
This is more likely to occur in babies/ young children with some birth defects in the soft palate, or if they have a cleft lip. Those birth defects, usually, get fixed with surgery when they are still children, that's why is less frequent after that age.
<span>Taxonomy is the classification or grouping of organisms into groups, based on shared or similar characteristics. The criteria used for including an organism in a group can be controversial. An example of a taxon is the class Reptilia.</span>
