单项选择题

Most American children start school by the age of 6. They attend 8 years of elementary school and 4 years of high school. Each state is responsible for its own education system and taxes are the main financial resources of free public schools. The Federal government contributes funds to the states for additional schools and school services. Educational requirements are set by state legislatures, but the management of the schools is left to the local communities.
Education is compulsory for all the children in America, so when the children reach a certain age, they are supposed to go to school. After graduation from high school, a student can further his education in a college, a university, or a specialized professional school — either public or private. Most colleges admit students on the basis of their high school records. Many students receive scholarships from the schools, the government, or private foundations and organizations. Over 50% of the college students work part-time to finance their education.
According to the passage, how do most colleges admit students