第12题: [单项选择]The pilot asked all the passengers on board to remain ______ as the plane was making a landing. A. seat B. seating C. seated D. to be seating 参考答案:C 答案解析:本题测试系表结构。过去分词常表示被动,但在 be seated,be hidden,be stationed,be dressed,be caught in,be lost,be born,be ti