Answer:
All of them. Plus feeding cows corn instead of grass makes them gassy.
Explanation:
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.
Answer: Option D
Explanation:
The practice which has been prevailing from a long time is considered as culture.Farming is also a type of culture which is being practiced from a longer period of time in the society.
The farming is also a type of culture which was invented somewhere and started spreading from there to other places.
This practice helped mankind in providing food and resources to the people of nation.