It is required that passengers remain when the plane is taking off or landing.
A. sit
B. seating
C. sat
D. seated
网友回答
A. sit
B. seating
C. sat
(答案→)D. seated
解析：考查形容词用法。Seated是过去分词转换的形容词，与系动词连用形成系表结构。Remain seated就坐，坐着；句意：据要求，当飞机起飞的时候，所有的乘客都要坐在位置上。故D正确。