College sports in the United States are a huge deal. Almost all major American universities have football, baseball, basketball and hockey programs, and (1) millions of dollars each year to sports. Most of them earn millions (2) as well, in television revenues, sponsorships. They also benefit (3) from the added publicity they get via their teams. Big-name universities (4) each other in the most popular sports. Football games at Michigan regularly (5) crowds of over 90, 000. Basketball’s national collegiate championship game is a TV (6) on a par with any other sporting event in the United States, (7) perhaps the Super Bowl itself. At any given time during fall or winter one can (8) one’s TV set and see the top athletic programs--from schools like Michigan, UCLA, Duke and Stanford-- (9) in front of packed houses and national TV audiences.
The athletes themselves are (10) and provided with sch61arships. College coaches identify (11) teenagers and then go into high schools to (12) the country’s best players to attend their universities. There are strict rules about (13) coaches can recruit--no recruiting calls after 9 p. m. , only one official visit to a campus--but they are often bent and sometimes (14) . Top college football programs (15) scholarships to 20 or 30 players each year, and those student-athletes, when they arrive (16) campus, receive free housing, tuition, meals, books, etc.
In return, the players (17) the program in their sport. Football players at top colleges (18) two hours a day, four days a week from January to April. In summer, it’s back to strength and agility training four days a week until mid-August, when camp (19) and preparation for the opening of the September-to-December season begins (20) During the season, practices last two or three hours a day from Tuesday to Friday. Saturday is game day. Mondays are an officially mandated day of rest.
13（）
A.which
B.what
C.how
D.whether