高中英语非谓语动词选择题,选哪个?

题目

高中英语非谓语动词选择题,选哪个?
After the meeting , Premier Wen Jiabao walked onto the platform ,______himself in a chair and prepared for answering the questions.

选 seated 还是 seating .请解释一下.
有的朋友会说选seated 表状态,表状态的话是因为词组 sb be seated 后面不接宾语,但后面有宾语 himself , 难道不应该是表主动吗,还是说himself不是宾语?

答案

seated
seat oneself 词组表示坐下
这里我感觉不是非谓语动词,而是动词,和伴随状语无关.因为你看这几个谓语都是平行的,walked... seated.and prepared.