当飞机降落时,乘务员要求旅客咀嚼食物,其目的是使耳中的____ 张开,使鼓膜内外的____ 保持平衡,从而防止对耳的损伤.
⑴Can I help you? ____ A. Of course.
⑵Are they OK?____ B. Yes.
⑶Can I try them on?____ C. Thank you.
⑷Here you are!____ D. No. They're too small.
①保护公民合法权益
②实现公民政治权利
③维护社会秩序
④促进司法公正