题目内容：

    United States health officials say an estimated 80,000 people died of influenza (流感) and problems resulting from the flu last winter, making it the worst season since 1977. The director for the U.S.Centers for Disease Control and Prevention (CDC) reported the number to The Associated Press. Health experts were expecting the winter of 2017-2018 to be a bad year for flu deaths, but not that.

Doctor William Schaffner is an expert on vaccines,  at Vanderbilt University in Tennessee. Schaffner noted that 80,000 deaths are nearly twice as much as what health officials once considered a “bad year”.

CDC officials say that between 12,000 and 56,000 Americans die every year from flu-related causes, but they do not have an exact count of how many people die from the flu each year. Influenza is a relatively common disease and not always listed on death records as the official cause of death. While last winter was a bad flu season in the U.S., it was not the worst. The 1918 flu lasted nearly two years. Historians estimate that the disease was to blame for between 500,000 to 700,000 deaths during that period. The exact number is still not known.

One thing that made the 2017-2018 flu season so bad was that the flu virus was strong. Usually the disease kills the very young, the very old or those who are already sick. However, last winter, the flu killed many healthy Americans. Another thing that made the flu season so deadly was that the flu vaccine was not as effective as experts had predicted. Drug makers have made changes to the vaccine. Even though the vaccine did not work well last year, health experts still strongly suggest getting vaccinated.

1.What can we learn about influenza in the first paragraph?

A.The winter of 2017-2018 saw the deadliest flu in history.

B.Effective cures should be found to deal with influenza.

C.Health experts had assumed flu would be severer.

D.More people died of influenza than expected in the winter of 2017-2018.

2.How many deaths did the health officials expect in a bad year?

A.80,000. B.40,000.

C.60,000. D.20,000.

3.Why can't CDC officials give an exact number of deaths from flu?

A.Because flu is always considered as a common disease.

B.Because people usually don't take flu seriously.

C.Because CDC officials are unwilling to count the deaths.

D.Because flu is not always listed on death records.

4.What do experts recommend people to do in the last paragraph?

A.Change the vaccine. B.Avoid using vaccine.

C.Get vaccinated. D.Do research on vaccine.