A、Tourism. B、Natural heritage. C、Illegal wildlife products. D、Slaughter of iconic animals. A演讲中男士提到，他们这些家庭只能眼睁睁地看着周围的野生动植物消失而失去了

Ladies and Gentlemen,
    Never before have we had so many different ways to talk to one another. In the distant past, written documents would be carried by hand across thousands of miles from China to Western Europe. Today, we access knowledge from all over the world, through our mobile phones, at the tap of a key. Wherever you are watching this program, whether in this hall, at work, with your friends, or at home with your families: Thank you for welcoming me into your homes.
    Many of the most important conversations we have in our lives take place in the family home. The home is where we learn from our parents and grandparents, teach our own children, and share our stories and hopes for the future. It is where many of our ideas and values are first kindles. In that spirit, there is one subject I believe we have to discuss, around our family tables and across the generations. It concerns the future, and I know the Chinese are a far-sighted people.
    It concerns particularly the environment, and I know that protecting China’s rich and beautiful natural heritage is important to all Chinese families. [23] It is the mass destruction and trafficking of iconic endangered species. And it is time to talk about the growing human demand for illegal wildlife products that drives the trade and makes it profitable.
    Today, we face an unprecedented surge in the brutal slaughter of iconic animals by poachers. In South Africa, for example, one rhino was killed every month until 2005. But last year, three rhinos were killed every single day. In the 33 years since I was born we have lost around 70 percent of Africa’s elephant population. [24] Of those that are left, 20,000 are being killed every year. That is 54 elephants killed every single day. At this rate, children born this year, like my daughter Charlotte, will see the last wild elephants and rhinos die before their 25th birthdays.
    Those who suffer the most from this loss are some of the poorest people on our planet.
    [25] They are the families who feel powerless as the wildlife around them disappear; who face being trapped in poverty forever without the income that should be brought in by tourism, a cornerstone of the economy in many developing nations. They are the children whose parents risk their lives in the fight against poachers. In the last few days, three rangers and one member of the Armed Forces were killed by poachers in one incident in central Africa; leaving behind 14 children between them. It is these children’s future that is blighted so tragically by the illegal wildlife trade, and it is their birth right that is stolen.
    There is no hiding from these facts today. On our phones, laptops and our TV screens, we can see the images and read the reports that lay bare the truth of this crisis. That knowledge brings responsibility: the responsibility to do everything in our power to reverse the march towards the eradication of these fine animals.
    The good news is that we are far from powerless in this struggle. We can turn the tide of extinction. We know where the animals we are trying to protect live. We know many of the roads, the airports and ports criminals use to transport their cargo from killing field to marketplace.
    And over the last few years we have seen a groundswell of action by governments to improve their laws and work across borders to fight the traffickers.
23. Which one is the main concern of the speaker’s speech?
24. How many left elephants are being killed every year?
25. What is the cornerstone of the economy in many developing nations?