A、Nearly one-fifth of them. B、Nearly two-thirds of them. C、Nearly half of them. D、Nearly all of them. A

Almost one-fifth of Europe’s wood beetles are at risk of extinction due to a widespread decline in ancient trees, according to a new report which suggests their death could have disastrous impact on other species. Wood beetles are a key food source for small mammals, bats and birds. Some species are also pollinators. Healthy and varied wood beetle populations need large volumes of dead and decaying wood. Some species will only lay their eggs in hollow holes containing mould that takes hundreds of years to form Logging and tree loss is “by far” the greatest threat to their way of life, the IUCN report says. But they also face an astonishing number of threats, from urbanization and tourism to arable farming, pollution and climate change. Dr. Keith Alexander, an ecological consultant who contributed to the report, said: “Wood beetles are intimately tied to everything else in the places where they occur. If you start to erode the varieties of life, then the ecosystem heads towards collapse.”
Questions 3 and 4 are based on the news report you have just heard.
3. How many wood beetles in Europe are at risk of extinction?
4. What is the greatest threat to wood beetles by far?