The List of World Heritage in Danger places sites subject to unusual levels of pollution, natural hazards, or other problems, until _________ are made.
举一反三
- The ratio of cultural to natural sites on the world heritage list is roughly __________.
- Among Chinese list of world heritages, there are ____________ world cultural and natural heritage sites till now.（ ） A: 4 B: 5 C: 6 D: 3
- Australia has nineteen properties inscribed on the world heritage list, three cultural sites, twelve natural sides. A: True B: False
- World Heritage Sites are classified into three types: cultural, natural and __________ heritage.
- UNESCO has not yet decided to put Venice on the list of World Heritage Sites In Danger. （ ）