Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
In early civilizations, citizens were educated informally, usually within the family unit. Education meant simply learning to live. As civilizations became more complex, however, education became more formal, structured and comprehensive. Initial efforts of the ancient Chinese and Greek societies concentrated solely on the education of males. The post-Babylonian Jews and Plato were exceptions to this pattern. Plato was apparently the first significant advocate of the equality of the sexes. Women, in his ideal state, would have the same rights and duties and the same educational opportunities as men. This aspect of Platonic philosophy, however, had little or no effect on education for many centuries, and the concept of a liberal education for men only, which had been espoused by Aristotle, prevailed.
In ancient Rome, the availability of an education was gradually extended to women, but they were taught separately from men. The early Christians and medieval Europeans continued this trend, and singlesex schools for the privileged classes prevailed through the Reformation period. Gradually, however, education for women on a separate but equal basis to that provided for men was becoming a clear responsibility of society. Martin Luther appealed for civil support of schools for all children. At the Council of Trent in the 16th century, the Roman Catholic Church encouraged the establishment of free primary schools for children of all classes. The concept of universal primary education, regardless of sex, had been born, but it was still in the realm of the single-sex school.
In the late 19th and early 20th centuries, co-education became a more widely applied principle of educational philosophy. In Britain, Germany, and the Soviet Union the education of boys and girls in the same classes became an accepted practice. Since World War II, Japan and the Scandinavian countries have also adopted relatively universal co-educational systems. The greatest negative reaction to coeducation has been felt in the teaching systems of the Latin countries, where the sexes have usually been separated at both primary and secondary levels, according to local conditions.
A number of studies have indicated that girls seem to perform better overall and in science in particular in single-sex classes: during the adolescent years, pressure to conform to stereotypical female gender roles may disadvantage girls in traditionally male subjects, making them reluctant to volunteer for experimental work while taking part in lessons. In Britain, academic league tables point to high standards achieved in girls' schools. Some educationalists therefore suggest segregation of the sexes as a good thing, particularly in certain areas, and a number of schools are experimenting with the idea.
The word "informally" in this context mostly refers to an education occurring _______.
