Question

1. our bones grow continuously throughout our lives, with old bone cells dying and being discarded. however, for astronauts who are in space for a prolonged period, a lack of gravitational pull—which has a number of beneficial effects on the body, including supporting new bone growth—results in their bones adding less bone tissue to replace dying tissue. in fact, for every month in space, a person will lose 1.5 to 2% of his or her bone mass, with the hip bone and the lower leg bones most affected. it can be inferred from the passage that: a. astronauts rarely regain their lost bone mass b. bone loss is not a problem for non - astronauts c. the lower body typically experiences more bone growth than the upper body d. astronauts seldom stay in space for more than a month

Explanation:

The passage mentions that for astronauts in space, lack of gravitational pull affects new bone growth and they lose bone mass, especially in hip and lower - leg bones. This implies that the lower body is more affected by bone - loss due to space conditions, which also suggests that under normal conditions (with gravitational pull), the lower body may have more bone growth compared to the upper body. Option A is not mentioned about regaining bone mass; option B is wrong as the passage only focuses on astronauts and doesn't say bone loss isn't a problem for non - astronauts; option D has no basis as there is no information about how long astronauts stay in space.

Answer:

C. the lower body typically experiences more bone growth than the upper body