A、Conducting heat. B、Storing energy. C、Transmitting signals. D、Tracking the users. B讲座中提到，我们的手机都有血腥的痕迹，这一切都源于一种在刚果开采的矿物质——钽。它是一种

Good morning, ladies and gentlemen. I want to talk to you today about a difficult topic that is close to me, and closer than you might realize to you.
    I came to the UK 21 years ago, from the Democratic Republic of the Congo. I want to tell you what the Congo has got to do with you. First of all, I want you to do me a favor. Can you all please reach into your pockets and take out your mobile phones? Feel that familiar weight...how naturally your finger slides towards the buttons. Can you imagine your world without it? It connects us to our loved ones, our family, friends and colleagues, at home and overseas. It is a symbol of an interconnected world.
    But what you hold in your hand leaves a bloody trail, and it all boils down to a mineral: tantalum, mined in the Congo. It is a heat conductor. It stores energy in our mobile phones, PlayStations and laptops. It would be great if the story ended there. Unfortunately, what you hold in your hand has not only enabled incredible technological development and industrial expansion, but it has also contributed to unimaginable human suffering. Since 1996, over five million people have died in the Democratic Republic of the Congo. Countless women, men and children have been raped, tortured and enslaved. The quest for extracting this mineral has not only aided, but it has fueled the ongoing war in the Congo.
    The mobile phone has given people around the world an important tool towards gaining their political freedom. It has truly revolutionized the way we communicate on the planet. It has allowed momentous political change to take place. At the moment, there is no clear fair-trade solution. But there has been a huge amount of progress. The US has recently passed legislation to target bribery and misconduct in the Congo. Recent UK legislation could be used in the same way.
    We demand fair-trade food and fair-trade clothes. It is time to demand fair-trade phones. This is an idea worth spreading. Thank you.
    Questions 23 to 25 are based on the recording you have just heard.
    23.What does the speaker say about the mobile phone?
    24.What’s the function of the mineral in mobile phones mined in the Congo?
    25.What was the consequence of the quest for the mineral in the Congo?