单项选择题


SECTION A CONVERSATIONS
In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.
Questions 1 to 3 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now, listen to the conversation.
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.