Almost 90 percent of American students below the college...

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to choose the word or phrase that best fits each of the numbered blanks from 25 to 29
Almost 90 percent of American students below the college level attend public elementary and secondary schools, which do not charge tuition but rely on local and state taxes for funding. Traditionally, elementary school includes kindergarten through the eighth grade. In some places (25) ________, elementary school ends after the sixth grade, and students attend middle school, or junior high school, from grades seven through nine. Similarly, secondary school, or high school, traditionally comprises grades nine through twelve, but in some places begins (26) ________ the tenth grade.
Most of the students who do not attend public elementary and secondary schools attend private schools, for which their families pay (27) ________. Four out of five private schools are run by religious groups. In these schools, religious instruction is part of the curriculum, (28) _________ also includes the traditional academic courses. There is also a small but growing number of parents who educate their children themselves, a practice known as home schooling.
The United States does not have a national school system. Nor, with the exception of the military academies, are there schools run by the federal government. But the government (29) _______ guidance and funding for federal educational programs in which both public and private schools take part, and the U.S. Department of Education oversees these programs.
The word or phrase which best fits the gap (28) is...
A. that
B. where
C. which
D. what