单选题 In the past 200 years, Australia has lost 19 species (种类) of animals and 76 species of plants.
The Australian National Parks and Wildlife Service estimates that between 100 and 250 million species of animals and plants have lived on Earth since life began about 3.5 million years ago. Today, there are between 5 and 10 million species, of which up to 1 million or more species could be extinct (灭绝) by the year 2010.
Today the council of state and federal ministers responsible for nature conservation (保护) has produced a list of currently endangered vertebrate fauna (脊椎动物). Three species of whale, various birds, a number of frogs, snakes and fish are also on the list.
But there is some cause for optimism (乐观). Several species previously believed extinct have reappeared in recent years.
This could mean that other "extinct" species may yet surface--even the Tasmanian tiger, which some authorities believe still exists in the remote regions of Tasmania.

A、 During the past two centuries, 19 species of animals have disappeared in Australia.
B、 Life on Earth is about 3.5 million years old.
C、 By the end of this century about one million species could become extinct.
D、 At least 250 million species of animals and plants have lived on Earth.