A、After their general survey courses are completed. B、After they enroll in a university. C、After they receive a bachelor of arts

Colleges and universities are degree-granting institutions of higher education.  In the original sense of the word, a college was a group of students who gathered to share academic and residential facilities. Each college was a component part of a corporate body called a university.  Today, especially in the United States, a college may be affiliated with a university (for example, Bernard College of Columbia University) or independent (for example, Smith College).
   American undergraduates traditionally have been required to take general survey courses before they specialize in major areas of concentration; the undergraduate program generally is four years, and each year is split into two or three semesters. After receiving a bachelor of arts (BA) or a bachelor of science (BS) degree, those who want additional education enroll in programs leading to a master of arts (MA) or a doctor of philosophy (Ph.D) degree or study at a medical, law, or other professional or technical graduate school at the same or another institution.
   In contrast, European students begin their higher education with specialized studies because their general education is completed in secondary school. In general, European universities have no prescribed courses, attendance requirements, or course grades. Students may attend lectures, but do their work directly with tutors who prepare them for examinations. Programs may be completed in two or six years.
15.What was the original meaning of the word "college"?
16.When do American students begin to specialize in their major?
17.When do American students begin to study at professional or technical graduate schools?
18.In what way is European higher education different from US higher education?