Biologists often define "longevity" as the potential lifespan an individual might achieve under
these optimal conditions involves various factors.
optimal conditions. Determining (27) _
studies are being conducted on how different types of physical activity, diet, and
certain
other lifestyle choices affect longevity. Researchers are also investigating (29) medications or supplements might extend lifespan. Over the past century, average lifespans have significantly increased, largely due to medical advancements that have reduced mortality from infectious diseases. For instance, in the early 20th century, the average lifespan was around 50 years. Today, life expectancy in many countries exceeds 75 years, with women generally living longer than men. On (30) _ people now enjoy a healthier, longer life, but scientists believe
humanity's maximum (31)
could be even higher with continued research and improved
living conditions.
Question 27. A. when
B. what
C. which
D. how
Question 28. A. Numerous
B. Much
C. Some
D. A lot
Question 29. A. if
B. whether
C. neither
D. either
Question 30. A. balance
B. purpose
C. average
D. measure
Question 31. A. lifestyle
B. lifespan
C. vitality
D. condition