Questions 43-46 refer to the following passage.        Making oneself relax in bubbling spring water is not only fulfilling - it's hcalthy, too! Forcenturies, people have been aware of the healing properties of mineral baths. Yet if simply soaking inthem is so beneficial, why not drink them as well? That was the reasoning behind one of the world'smost popular types of beverages known today as soft drinks.        Inspired by the creativity of his good friend Benjamin Franklin, scientist Joseph Priestleycreated the main ingredient of the popular beverage by discovering a method for mixing water withcertain gases. He placed a bowl of water above a vat of fermenting beer. The beer then gave offcarbon dioxide, which is mixed with the water, and bubbling soda was born.        Priestley began to serve the soda water to his friends, who were contented with its pleasanttangy taste. Medicinal and other pleasant-tasting herbs were soon added to it, gradually increasing itspopularity as a health drink.       Over the next several decades. Priestley's carbonated water, also called soda, took on manydifferent flavors. Adding citric acid to it led to carbonated lemonade. Flavoring it with ginger rootresulted in ginger ale. All claimed to have some sort of healing property, and were only available indrugstores.        In 1832, John Matthews invented the soda fountain, and soda really took off. His machinemixed carbonated water with flavored syrup. The soda fountains inside drugstores became popularhangouts for people secking "health" drinks.       It took more than 50 years, however, for the carbonated drinks we know today to appear.Soda's popularity soon exploded, becoming a favorite among people of all ages. Lively hangoutscalled soda cafes, serving soda, food, and a rocking good time, soon replaced drugstore sodafountains.        Most recently, diet, sugar-free, and caffeine free alternatives have been added to the alreadylarge selection of soft drinks. The thirst for them has turned the soft drink industry into a billion-dollarbusiness. And all over the world, pcople seeking a quick pick-me-up continue to gulp down thebubbling drinks.
【題組】43. What are the key components of bubbling soda?
(A) Water and beer.
(B) Water and carbon dioxide.
(C) Water and medicinal herbs.
(D) Mineral water and syrup.