（Ⅰ）求函数f（x）的定义域；
（Ⅱ）是否存在实数a，使函数f（x）为奇函数．
解得：x≠0
∴函数f（x）的定义域为{x∈R|x≠0}．
（Ⅱ） 解法一：
函数定义域关于原点对称，假设存在实数a使函数f（x）为奇函数，那么必有f（x）在x=±1时均有定义，
且f（x）为奇函数，
∴ f(
用所给的单词的适当形式填空
①This is the ____ (one) time for me to see you.
②November is the ____ (eleven) month of the year.
③ My ____ (sister) birthday is on November 12.
④ September 10 is ____ (teacher) Day.
⑤ ____ (she) birthday is on May 5.
⑥ The ____ (five) lesson is very interesting.
根据文意填入横线处的词恰当的一项是（ ）
一个大师知道，经过若干年之后，在________和________技艺上停滞不前是最愚蠢的。他们告诉自己：一种经验（无论那可能是多么痛苦的经验），一个微不足道的观察，一次彻底的调查，欢乐和忧伤，失败和胜利，以及梦想、臆测、幻想，无不以________或________方式给他们的工作带来益处。
People in different countries have different ways of doing things. Something that is polite in one country may be quite impolite in another. In Britain, you mustn't lift (举起) your bowl to your mouth when you are having some soup. But it's different in China. And in Japan you even needn't worry about making a noise when you have it. It shows that you are enjoying it. Making a noise is considered as (被认为) bad manners (举止，礼仪) in Britain. If you are a visitor in Mongolia, what manners do they wish you to have? They wish you to give a loud “burp”(打嗝) after you finish eating. Burping shows that you like the food. In Britain, you should try not to put your hands on the table when you’re having a meal. In Mexico, however, they hope you keep the hands on the table during a meal. But Arabians consider you must be very careful with your hands. You mustn't eat with your left hand. Arabians consider it very bad manners eating with left hands. So, what should you do if you are on a visit in another country? Well, you can ask the local people to help you or just watch carefully and follow them if you are on a visit in another country.
一边……一边……：
