图1是小黄家一台快速电热水壶，铭牌如左下表．为了测量它烧水时的实际功率，小黄和父亲合作进行了如下实验：关掉家里所有用电器，将该电水壶装了0.5L、20℃的水，接入家庭电路中，闭合壶的开关，测得壶中的水从20℃上升到100℃所用的时间是7min．同时观察到家中电能表（见图2（b）转过的转数正好为175转（r）．

请根据相关信息求：

体育课上，老师口令是“立正，向左转” 时，你的身体____旋转了____度。

阅渎材料，回答问题：

材料一：  2013年9月7日，***主席在哈萨克斯坦首提共同建设“丝绸之路经济带一个月后，***在印度尼西亚首提”21世纪海上丝绸之路”。一带一路即二者的合称。一带一路是未来几十年内国家层西的大战略，必将影响深远。2014年3月***主席在德国科尔伯基金会发表讲话：“历史上郑和下西洋，通过海上丝绸之路推行经贸和文化交流，舰队这么强大却没有进行过任何侵略，而是调解纠纷，打击海盗……”

材料二：

    It is popular to travel by bike in China. China has a huge population. And it is said that there is at least one bike for every two people. Of course, many people in China ride bikes for sport or exercise, but it is also a much more commonly accepted means of everyday transportation, as compared to countries such as the United States.

    If you are living for a long time in China, chances are that you will want to buy your own bike so that you can use it whenever you want. Even if you don't use a bike for everyday transportation, owning one can be a great way to enjoy the sights in the countryside. However, if you are just visiting China, renting a bike can be a more convenient choice.

    It is important to choose the correct bike for your use. You will find that in China, the one-speed style of bike is popular. These bikes are great if you want to ride around in the city to see the sights. They are quite comfortable and easy to ride. You can often rent a bike for a day for about 15 dollars.

    However, if you wish to ride on some of the rural paths, a mountain bike style would be a better choice. They are great for different kinds of road surfaces, providing for a safer ride. If you are planning to have a wish to tour and still be able to carry packages with you, then a touring bike would be the best choice. These are the most expensive to rent, but are very suitable for carrying packages and even some of your luggage along with you.