Question

which is a symptom of cystic fibrosis?
digesting food too quickly
lack of ability to strengthen muscles
thick layer of mucus that can block airways

Explanation:

Cystic fibrosis is a genetic disorder that affects the production of mucus, sweat, and digestive juices. In cystic fibrosis, the mucus becomes thick and sticky. This thick mucus can block airways in the lungs, leading to breathing difficulties and increased risk of lung infections. Digesting food too quickly is not a typical symptom (in fact, digestive issues like poor nutrient absorption due to thickened digestive juices are more common). Lack of ability to strengthen muscles is not a direct and characteristic symptom of cystic fibrosis. The thick mucus blocking airways is a hallmark symptom related to the respiratory system manifestations of cystic fibrosis.

Answer:

thick layer of mucus that can block airways