Which of the following description about islet hormones is correct? A: Pancreatic alpha cells produce glucagon B: Pancreatic beta cells produce insulin with low glucose C: Somatostatin produced by pancreatic delta cells enhances insulin secretion D: Somatostatin produced by pancreatic delta cells enhances glucagon secretion E: Insulin can pass through the plasma membrane

Under a certain long-term load, concrete would creep. In the reinforced concrete axial compressive members: A: Creep increases the compressive stress of concrete. B: The compressive stress of concrete and steel bar keeps unchanged. C: Creep decreases the compressive stress of concrete and increases the compressive stress of steel bar. D: Creep increases the compressive stress of concrete and decreases the compressive stress of steel bar.

Which of the following can lead to increases of both AB and SB? A: Acute respiratory acidosis B: Chronic respiratory acidosis C: Acute respiratory alkalosis D: Chronic respiratory alkalosis E: Acute metabolic acidosis

Which of the following is primarily responsible for the functional<br/>changes of cardiovascular system in stress response ? () A: Central<br/>nerve system B: Hypothalamus-pituitary-adrenal cortex system C: Sympathetic-adrenal medulla system D: Glucagon and insulin E: Immune system

Under the same material conditions, as the flexibility increases, ( ). A: The critical stress of the long column decreases while that of the medium flexibility bar remains unchanged. B: The critical stress of the intermediate column decreases while that of the large flexibility bar remains unchanged. C: The critical stress of the large and the intermediate column are both decreased. D: The critical stress of the large and the intermediate column are both unchanged.