<P> Under the educational reform tenets, polytechnic colleges were to give priority to admitting secondary vocational and technical school graduates and providing on - the - job training for qualified workers . Education reformers continued to press for the conversion of about 50 percent of upper secondary education into vocational education, which traditionally had been weak in the rural areas . Regular senior middle schools were to be converted into vocational middle schools, and vocational training classes were to be established in some senior middle schools . Diversion of students from academic to technical education was intended to alleviate skill shortages and to reduce the competition for university enrollment . </P> <P> Although enrollment in technical schools of various kinds had not yet increased enough to compensate for decreasing enrollments in regular senior middle schools, the proportion of vocational and technical students to total senior - middle - school students increased from about 5 percent in 1978 to almost 36 percent in 1985, although development was uneven . Further, to encourage greater numbers of junior - middle - school graduates to enter technical schools, vocational and technical school graduates were given priority in job assignments, while other job seekers had to take technical tests . </P> <P> In 1987 there were four kinds of secondary vocational and technical schools: 1) technical schools that offered a four - year, post-junior middle course and two - to three - year post-senior middle training in such fields as commerce, legal work, fine arts, and forestry; 2) workers' training schools that accepted students whose senior - middle - school education consisted of two years of training in such trades as carpentry and welding; 3) vocational technical schools that accepted either junior - or senior - middle - school students for one - to three - year courses in cooking, tailoring, photography, and other services; and 4) agricultural middle schools that offered basic subjects and agricultural science . </P> <P> These technical schools had several hundred different programs . Their narrow specializations had advantages in that they offered in - depth training, reducing the need for on - the - job training and thereby lowering learning time and costs . Moreover, students were more motivated to study if there were links between training and future jobs . Much of the training could be done at existing enterprises, where staff and equipment was available at little additional cost . </P>

Which of the following subjects are not mandatory in chinese middle schools