Ebola. The very word sends a chill down many people’s backs. It is a mysterious and fatal disease. Scientists still don’t really know __35__ people originally get infected, and there is no cure or vaccine to help those who have been infected. Most Ebola cases have occurred in Central Africa, infecting over 1,500 people and causing over 1,000 deaths in total over the past 30 years.    Humans initially get infected from monkeys, but scientists can’t assure that monkeys are the carriers. As being infected, the patient will have all __36__, including fever, head and muscle aches, vomiting, and internal and external bleeding. Ebola is able to spread easily and quickly by __37__ with infected blood, other bodily fluids, or dead patients. The only help that a doctor can give Ebola patients is to keep them hydrated with enough water—and isolated the patient from other people. __38__ this is a fatal disease, fortunately its overall impact may be somewhat limited. Each previous outbreak only infected a few hundred individuals and was usually over within a few weeks. Also, because of the Internet and modern medical science, new outbreaks are identified much earlier than before, and teams of international doctors can fly to and quarantine the site before too much harm can be done.
【題組】35.
(A) that
(B) how
(C) why
(D) what