Passage 3 There is a vital need for national parks. We must have them as places where plants and animals can be preserved in the natural state for all time. And we need parks as a retreat (休养所) from the crowded bustling life of cities. Our record for conservation (自然资源保护) is poor. Half of the animal species existing at the time of Captain Cook.s arrival are now extinct（灭绝）. Australia has wildlife (野生生物) that is not found in the native state in any other part of the world. This wildlife is therefore of particular scientific value. In New South Wales, the National Parks and Wildlife Service is responsible for the care of out native plants and animals in their natural environment. One of the aims of this service is to educate people in the need for conservation. The service also provides facilities for recreation (娱乐) in parks and wilderness areas throughout the state. A UNESCO (联合国教科文组织)study stated that a country should strive to retain 5 percent of its land as national parks. Australia at present is below this figure but there is a community awareness of the need to increase it and new areas are being proclaimed almost annually. In the years to come, our national parks will be one of our most valuable assets. As our population grows and our cities become more crowded，parks will become vital as retreats from the pressures of modern urbanized living.
41．Judging from the passage，when Captain Cook first arrived in Australia，________.
