Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

Ha Long Bay is a UNESCO World Heritage site in Quang Ninh province, in the northeast of Viet Nam. It has got over 1,600 islands and islets. Among the many ancient fishing villages in Ha Long Bay, only Cua Van floating village remains. All the houses and buildings in the village float on huge wooden rafts.

The villagers spend their days fishing and looking after the sea life. Then they sail to the mainland to trade their fish for things like food, drinking water or clothes. Most children go to floating schools and then spend the rest of their time learning important skills like swimming and fishing. They also help out their parents as much as they can.

Their lifestyle may seem strange to many people, but it’s so wonderful to live among such natural beauty and know you are protecting it. The villagers are able to help preserve their beautiful bay because they live directly on the water.

The word "they" in paragraph 2 is closest in meaning to ________.