句型转换

根据短文理解, 从A、B、C三个选项中选择最佳答案填空。

    Paris, the capital of France, is a very special place. It's one of the Europe's 1 cities. People have lived there 2 more than 2, 000 years. Most people like it, but for different  3.

   Lovers and young people think  4 a very romantic(浪漫的) place. They like to walk 5 the Seine River(塞纳河) and drink coffee in small shops. Artists find many interesting things to 6. Tourists love shopping and visiting the famous places, 7 the Eiffel Tower and Louvre Museum. People who like 8 enjoy walking down old streets and seeing old buildings.

    In Paris, Hotels, food, and other things are 9. But there's something funny about that. In Paris, people have such a good time that they don't want to 10!

下面是某学生在课外做“比较材料的隔声性能”活动时记录的一些内容：

【器材】：一个能发声的电子铃，一个鞋盒，待比较的材料（棉布、报纸、塑料布、泡沫塑料及其它材料）、一把长卷尺．

【步骤】：小明先将衣服包好电子铃，放入盒内，让其发声．再安排一位同学远离盒子直到听不到铃声时为止，用卷尺测出同学到盒子的距离．换用其它材料完成上述步骤．

【提问】：①小明是通过____ 来比较材料隔声性能的．这种方法叫____ ．

②小芳认为：比较的时候，远离的方向要相同，因为风向不同会影响声音的传播（这种方法叫控制变量法）．请你想一想，还要保持哪些因素相同呢？写出两个：____ 、____ ．