第 23 至 25 題，請依照下列的文章，選出最適當的答案。                                    Winter Heralds the Arrival of InfluenzaInfluenza       is transmitted easily from person to person. You may come in contact with it today simplyby talking to your colleague. Even if you are healthy, it may keep you in bed feeling miserable for weeks.Symptoms include fever, aching muscles, runny nose, cough, sore throat, and fatigue. For those who havepreexisting health problems, influenza can be severe.What is influenza? It is a contagious disease caused by a virus that infects the respiratory tract of thebody. It typically infects ten to twenty percent of the world’s population each flu season.How can you prevent it?A) Vaccination: The influenza vaccination is 70 to 90 percent effective. It’s a single shot given eachyear prior to the flu season.  B) Hygiene: Wash your hands frequently whether you are sick or healthy. Use a mask when in closecontact with people exhibiting symptoms of the flu. Decontaminate your home and working environmentby cleaning with products containing bleach.       National Health is committed to offering a high-level service at affordable prices to encourage allCanadian residents to get vaccinated. To schedule your flu vaccination, call our office at 02-2505-1920 orvisit our website at www.nationalhealth.com. Office hours are 8 am to 5 pm, Monday through Friday. Walk-ins welcome.
【題組】23. When should people get a vaccination?
(A) When they have the flu
(B) Every two months
(C)After the flu season
(D) Before the flu season