Seafaring has, through history, always been one of the most dangerous occupations. Even today that is still true. Many countries had unilateral regulations on safety (1) _______ sea trade is of international nature, the rules and regulations (2) ________ be set up internationally, (3) ________ by individual countries, to make them better overall. To improve this subject, in 1948 the basis was laid for IMO.
(Ship Knowledge - A Modern Encyclopedia - K. Van Dokkum 2003)
Choose the correct answer that fills the blank space (1).