The 1980s and 1990s were bad times for the Tibetan antelope. Hunters were shooting antelopes to make profits. Their habitats were becoming 【小题1】 (small) as new roads and railways were built. In order to save this species 【小题2】 extinction, the Chinese government placed it under national protection. Volunteers watched over the antelopes day and night 【小题3】 (keep) them safe from attacks. Bridges and gates were added to let the antelopes move 【小题4】 (easy) and keep them safe from cars and trains.