A、AIDS. B、Malaria. C、Pneumonia. D、Cancer. C本题问的是根据短文中的描述，引起青少年死亡的头号杀手是什么。文中提到肺炎是青少年的头号杀手，它引起的死亡人数要比艾滋病和疟疾加起来还要多。

Millions of babies and children could soon be protected against the deadly disease pneumonia(肺炎).(16)Two leading drug companies have agreed to supply vaccines(疫苗)against pneumonia to the world’s poorest countries at a reduced price, and they signed the historic Advance Market Commitment Agreement last week. The Global Alliance for Vaccines and Immunizations(GAVI)helped negotiate the deal. The group says the low-cost vaccines could save as many as seven million lives by the year 2030.(17)The World Health Organization says pneumonia kills almost two million children each year. This is more than AIDS and malaria(疟疾)combined. It is the leading cause of death among young children. And, more than 90 percent of those deaths happen in the developing world. Last year, the governments of Italy, the United Kingdom, Canada, Russia and Norway joined with the Bill and Melinda Gates Foundation. They provided 1. 5 billion dollars to launch the pneumonia vaccine project. Jeffrey Rowland is with the GAVI alliance. He said, "Many people tend to take vaccination for granted in countries like the United States or in Western Europe, but in fact a lot of us don’t even know which diseases we’ve been vaccinated against. That’s not the case in poor countries.(18)Vaccination is a life or death question for poor people and if you can vaccinate a child to prevent a disease from happening, it is a lot more effective than it is to treat that disease afterwards."
16. What does the speaker say about Advance Market Commitment Agreement?
17. According to the passage, what is the leading cause of death among young children?
18. What can we learn from Jeffrey Rowland’s remarks?