Most of us have probably1of Mickey Mouse, Donald Duck, and many other famous Disney characters. Perhaps we have even seen them in movies. But have you ever2to Disneyland? 3fact, there are now four4Disneyland amusement parks around the world. Two are in the United States, one is in Japan, and5 is in France.
    Disneyland is an amusement park, but we can 6call it a theme park. It has all the normal7that you can find at an amusement park, but it also has a theme. The theme, of course, is Disney movies and Disney characters. For example, you can find a roller coaster in most amusement parks, but in Disneyland, the8of the roller coaster is Disney characters. This means that you can find Disney characters all over the roller coaster. You can also 9Disney movies, eat in Disney restaurants, and buy Disney gifts. And you can see Disney characters 10around Disneyland all the time.

①烧杯   ②胶头滴管   ③1000mL容量瓶   ④500mL容量瓶   ⑤玻璃棒 ⑥托盘天平（带砝码）  ⑦酒精灯  ⑧药匙

地表平均气温约15℃，温度适宜，这一环境特点与下列因素关系不大的是（    ）

在由CH₄和H₂组成的混合气体中，测知碳元素的质量分数为60%，则混合气体充分燃烧生成二氧化碳和水的质量比为（　　）

某同学想通过实验来探究“影响滑轮组的机械效率的因素”．他做了如图所示的实验，并测算了各次实验装置的机械效率．关于他的实验过程，下列说法中不正确的是（　　）