【单选题】Which of the following statements about the harmful effects of hemoglobin bound with CO (COHb) is wrong?
A.
At levels of less than 10% of total hemoglobin, symptoms are rarely observed. At 15%, the individual experiences mild headaches.
B.
At 20% to 30%, the headache is severe and is generally accompanied by nausea, dizziness, confusion, disorientation, and some visual disturbances; these symptoms are not generally reversed if the individual is treated with oxygen.
C.
At COHb levels of 30% to 50%, the neurological symptoms become more severe, and at levels near 50%, the individual loses consciousness and can sink into coma. Respiratory failure may follow. With prolonged exposure, some damage becomes permanent.
D.
Death normally occurs when COHb levels rise above 60%.
【简答题】Commercial airliners are generally (1) _______ by two operators, a captain and a co-pilot. The captain is (2) __________, and carries the responsibility for decisions made during the course of a fligh...
【判断题】水合物分子式:一般用M·nH2O 表示,M为水合物中的气体分子,n为水分子数。如CH4·6H2O,C2H6·6H2O,C3H8·17H2O,i C4H10·17H2O ,H2S·6H2O,CO2·6H2O。Molecular formula: generally expressed as M·nH2O, where M is the gas molecule in hydrate and n is...
【简答题】听力填充: Commercial airliners are generally (1) _______ by two operators, a captain and a co-pilot. The captain is (2) __________, and carries the responsibility for decisions made during the course of a...