SECTION A CONVERSATIONS
Directions: In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.
听力原文：W: Oh, David. I just can't believe it. There are more than forty million people who have HIV in the world, 70 percent of them in Africa, and the former Soviet Union and parts of Asia are also big risk areas.
M: The UN AIDS organization last week estimated that in just over 20 years, 20 million people have died of AIDS, and this figure will be 3 times in the next 2 decades unless a major rescue effort is launched in poor countries.
W: That sounds really terrible! Something must be done to it.
M: Yes. The 14th International AIDS Conference was held in Barcelona. It's aiming at increased global awareness of the threat of the killing epidemic to the economic development, peace, security and mobilized resources to cheek the spread of HIV. I've heard there's breakthrough in technology. But the fight against AIDS will be long.
W: Many people argue that AIDS victims should be separated. What do you think about it？
M: Separating will help no one. Most AIDS patients are too sick to be transmitting the virus. Largely people who do not have AIDS but axe infected with the HIV virus are spreading the virus, and they may or may not know it. Separation would be totally futile.
W: Would mandatory testing help？
M: I believe it would drive every people you want to test underground. Voluntary, confidential testing is much more appropriate.
How many people are there in Africa infected with HIV？

A. 40 million.
B. About 28 million.
C. 12 million.
D. Less than 28 million.