Option 1:
Measuring the heights of every fiftieth person on the school roster to determine the average heights of the boys in the school
Comment: this might not be a good idea for fairness as we only wish to determine average height of the boys. Taking a group of 50 people randomly, might not give us the same number of boys every time.
Option 2:
Calling every third person on the soccer team’s roster to determine how many of the team members have completed their fundraising assignment
Comment: The context doesn't seem to need a sampling. The number of players in a soccer team is considerably small. We can find exact data by asking in person.
Option 3:
Observing every person walking down Main Street at 5 p.m. one evening to determine the percentage of people who wear glasses
Comment: To get a more accurate result and fairer sampling, the period of observing could have been longer, for example, observing for 12 hours on that day, or an alternative is to observe at 5 pm for 7 days in a row. It could happen that no one walking down the Main street precisely at 5 pm wears glasses, or it could happen the other way around.
Option 4:
Sending a confidential e-mail survey to every one-hundredth parent in the school district to determine the overall satisfaction of the residents of the town taking a poll in the lunch room (where all students currently have to eat lunch) to determine the number of students who want to be able to leave campus during lunch.
Comment: This sampling does fairly represent the population, although it might be an idea to scale down the sample population, i.e. every fiftieth parent.
Answer: Option 4
The correct answer is, D. It will follow a general noun and is not set
off by commas. A restrictive adjectival clause (also called essential
clause) is essential to the meaning of sentence because it refers to
specific noun in sentence. Deleting this clause will change the meaning
of the sentence. Since these are essential, the are not set off by
commas. E.g. All students who have scored more than 80 percent will move
to next round.
Answer:
I think it's letter A.
not sure my answer correct me if my answer is wrong:)
Answer:
Species interactions within ecological webs include four main types of two-way interactions: mutualism, commensalism, competition, and predation (which includes herbivory and parasitism). Because of the many linkages among species within a food web, changes to one species can have far-reaching effects.
Explanation:
