A、The workaholics. B、The alcoholics. C、Those who lack physical exercise. D、Pregnant women. D

M: Flu season is not easing its grip on much of the United States, and the outbreak is reaching levels not seen in nearly a decade. It has claimed the lives of at least 10 more children this week, putting that number at 63 for the season. Tens of thousands of deaths are often associated with the flu annually. Dr. Anne joins me now. So, how widespread is the flu right now in this country?
    W: This is a very difficult flu season. And this past week, we got more bad news. The doctor visits for flu are as high this week as we have seen during the peak of the 2009 epidemic. We’re not having an epidemic right now, but we have a very, very difficult flu season.
    M: Why is it so bad this year?
    W: Well, there are a couple of reasons that we know of, and there are probably some more reasons that we need to learn about. One thing is it’s an H3N2 influenza season. That’s the virus that’s dominating. There are a couple of other viruses circulating. H3N2 seasons tend to be more severe. The other thing is that influenza vaccine doesn’t work as well against H3N2 virus, so that’s probably a second factor.
    M: Are there particular parts of our population that are more vulnerable than others?
    W: Anyone can get the flu, and it can be serious. But the people who have a harder time with flu are the very old, the very young, pregnant women, and people with heart disease, lung disease, and other medical conditions that can make it harder for them to take on a lung infection.
    M: What is your recommendation then?
    W: We recommend that those groups in particular, if they present with flu symptoms, they can benefit from antiviral medicines that may convert a relatively mild illness. That may prevent a milder illness from becoming a hospitalization or worse.
    Questions 1 to 4 are based on the conversation you have just heard.
    1. What can we learn about the flu in the US?
    2. Why is the flu so bad this year according to the woman?
    3. Who are more vulnerable to the flu according to the woman?
    4. What does the woman suggest vulnerable people do when presenting with flu symptoms?