阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第2～5段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。
Trade Unions
1．Some scholars have associated trade unions with the medieval craft guilds(中世纪的行会), but there are important differences between the two. The guild members were master craftsmen who owned capital and often employed workers. Unions are known as associations of workers with similar skills.
2．In the past, individual workers had no control over the conditions of their working lives; political and economic power was concentrated in the hands of wealthy business owners. Workers found, however, that there was strength in uniting. From their earliest years, union objectives have been higher wages and improved working conditions.
3．Employers resisted, of course. They made great efforts to stop union organizing its activities. Union members were fired, workers were forced to sign contracts in which they promised not to join a union, and companies hired strikebreakers (罢工破坏者) and even gunmen to frighten organizers.
4．One of the earliest successful labor organizations in the United States was the Knights of Labor, founded in 1869. The Knights, which included both skilled and unskilled workers, attempted to organize all workers into one great union. After it successfully struck the Wabash railroad owned by Jay Gould in 1885, its popularity and power grew dramatically. In 1886 the Knights had 700,000 members.
5．The decline of the Knights of Labor, however, came quickly. The strike against Gould was gradually broken, and the Knights’ radical positions on social issues cost them public support. In the end, a lack of unity as well as the rapid inflow of unskilled immigrants weakened the union’s economic power, and the organization came to an end. Paragraph 4 ______