单项选择题
A．smokers should not expect to become airline pilots B．smoking in emergency cases causes mental illness C．no airline pilots smoke during flights D．smokers may prove unequal to handling emergency cases
A．beat B．envied C．caught up with D．made the best of
A．to test whether smoking has a positive effect on the mental capacity of smokers B．to show how smoking damages people' s mental capacity C．to prove the smoking affects people' s regular performance D．to find out whether smoking helps people' s short-term memory