Three groups of cyclists shown above consumed three different types of diets: high-carbohydrate, a diet mixed in carbohydrates, fat, and protein, or a diet higher in protein and fat. The average time each group could spend cycling over a 6-hour period is shown in the above graph.
How could an athlete or trainer use the data to improve performance?
A) Endurance is entirely related to diet.
B) Maintaining elevated blood sugar improves performance.
C) An early and dramatic drop in blood glucose is associated with improved endurance.
D) Diet is not at all related to endurance.

The function of mechanical digestion is to break down large chunks of food into smaller pieces. Why is this important?
A) Smaller pieces of food do not taste as good as larger pieces of food.
B) Smaller pieces of food have more surface area for chemical digestion than do larger pieces of food.
C) Smaller pieces of food are easier to excrete than are larger pieces of food.
D) Smaller pieces of food are more easily stored in the stomach than are larger pieces of food.