“手里没有苹果，感觉不入流。果粉‘爱疯死’，宠坏洋品牌”。iPhone6S在中国内地市场一上市就受到了无比热情的追捧。据此回答问题。

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．

（B）

    Traveling is very interesting. Many people love traveling. There are many ways to travel: by plane, by train, by ship or by car. Everyone has their favorite way.

Greg:

    My favorite way of traveling is by car. I can bring my pet dog along. I can travel three hundred miles or only fifty miles a day. I can stop at a good restaurant to enjoy a good meal or at a hotel to spend the night.

Eliza:

    I love traveling by train best! It's very exciting. I traveled most of Europe in 5 months by train. It's the best way to talk with the local people and make new friends on the way. Trains make even the longest trip enjoyable. The train ride to me is just like a big moving party.

    I also like traveling by ship. It is a very great way to spend a vacation. I can go to parties and movies on the ship, and enjoy the blue sky and water.

Danny:

    Planes are my favorite. It's the fastest way of traveling. I can quickly get to another country. Planes have very comfortable seats. I can have something to drink and to eat. I can also read some free magazines and newspapers.

1940年12月，罗斯福说：“过去两年的经验已经证明，任何国家都不能姑息纳粹，一个国家只有以彻底投降为代价才能与纳粹和平。”下列哪个国家的事实证明了这一论断（    ）