The <u><em>correct answer</em></u> is:
He needs to select a more representative sample.
Explanation:
Choosing students from the basketball team for the sample he uses on a study of heart rates and exercise will be a biased sample. This is because students on the basketball team are potentially healthier than other students, which means that exercise will not have a large an effect on their heart rate as it would if they were not as healthy and not as physically fit.
In order to reduce the amount of bias, he should choose students from different groups throughout the school.
Considering answers;
-fever
-constricted veins
-swollen veins
-confusion
Answer;
Swollen veins
Swollen veins might be a symptom of a person whose vein valves are not functioning properly and are causing fluid it flow away from the heart.
Explanation;
Valves are structures that are found in the circulatory system both in the heart and the veins.
They function to prevent the back flow of blood.
They do so by ensuring the continuous flow of blood in one direction.
If the valves are not functioning properly it may lead to various effects such as swollen veins due to the back flow of blood which may lead to the pooling of blood in the extremities.
i think its energy that made by our body.. its form from a chemical substance (from food). The chemical energy in our body is the heat we give.
Answer - True
Reasoning - The reason is without predation the animals will die since if they won't hunt they won't eat and die. Yes it's important to because it helps maintain the ecosystem. For example a Tiger is on top of the food chain so it's to gotta hunt. Just like down those line of chains.
