下面为某家族白化病（皮肤中无黑色素）的遗传系谱，请据图回答（相关的遗传基因用A、a表示）
II3的可能基因型是（）
参考答案：AA/Aa
All passengers _______, please fasten your seat belts and remain seated _______ the plane is landing.
A．on board; until
B．abroad; since
C．on the board; before
D．aboard; when
