You want to know about my staying in America, right? Well, to tell you the truth, it is really an eye-opening experience to study here.
In China, I had English classes five times a week since fifth grade. However, I didn't know how different textbook English could be from everyday English until I came to Hotchkiss School, Connecticut.
When I first studied English, I was told to say,” I am fine” when people say “How are you?” But in the US, I found that people say, “I am good” or “I'm tired”.
    One day, someone greeted me with “What’s up?” It made me confused . I thought for a moment and then smiled because I didn't know what to say.
    Since then, I have discovered more and more differences between Chinese and US cultures.
    To my surprise, US girls spend a lot of time in the burning sun to get a tan(晒黑). However, in China, girls try every possible way to get their skin paler, or “whiter”.
    I was also surprised by how hardworking US students are.  In China, schoolwork is almost everything, so we study hard and that's it. But here, a “good” student gets good grades, does a lot for the public and plays sports or music.
    The kids here are so talented, I am starting to be sorry that I gave up playing the piano at an early age and that I have never thought about sports.

小明猜想，水中加入别的物质后，一定会对水的凝固点产生影响，为了验证这一猜想，他将一些盐放入水中，并把盐水用容器盛好放入冰箱，研究盐水的凝固过程．每隔一定时间，小明就观察盐水状态、测出温度，并将凝固过程记录的温度数据画成了凝固图象如图所示。

（1）从图象中可以看出盐水从第　 ____　分钟开始凝固，凝固过程用了　 ____　分钟。

（2）凝固点为 ____　℃．实验验证了小明的猜想，因为与水相比，凝固点变 ____了（选填“高”或“低”）。

（3）如果将一个装有冰水混合物的试管放入正在熔化的盐冰水混合物中如图所示，试管中的冰水混合物中的冰会 ____（选填“变多”、“变少”或“不变”）。

在一次“飞车过黄河“的表演中，汽车在空中飞经最高点后在对岸着地，已知汽车在最高点时速度为40m/s，从最高点至着地点的水平距离为32m，忽略空气阻力，g=10m/s²．求：

①说中国人失掉了自信力，用以指一部分人则可，倘若加以全体，那简直是       。

②前行是       的。熟悉的树木、村庄、桥梁……都在不停地后退，成为杜小康眼中的遥远之物。

③一九二六年九月一日，天津出版了两张报纸，停刊了几年的《大公报》由李鸾、胡政之等接办重新复刊，         ，大家都接连称赞。

④人学仪式当天校长就要求我们进入大学就要遵守大学的一切规章制度，学好相应的课程，做一个         的大学生。