請依下文回答第 46 題至第 50 題
Researchers have pointed out that it is important to know one’s blood type. When Harvard
scientists 46 more than two decades of data on more than 77,000 people, they found that people with type AB
blood had a 23 percent increased risk for heart disease compared to people with type O blood. 47 with type B
blood had an 11 percent higher risk and people with type A blood had 5 percent greater risk of heart disease.
Researchers aren’t sure 48 , though. But they posit that type A blood is associated with LDL cholesterol
and that type O blood, 49 is associated with reduced risk, may contain a chemical that boosts blood flow and
prevents clots. However, researchers are quick to point out that lifestyle factors 50 weight, smoking, and diet,
which, unlike blood type, are modifiable and have a much greater impact on heart disease. 【題組】47 (A) Some (B) All (C) Those (D) These