P是四边形ABCD内一点，PA=PB=PC=PD，又AB=CD，试确定四边形ABCD的形状，并加以证明．

单词拼写，根据句子中所给的单词首字母或中文提示，填写正确的单词。

(1)Doing the boring work all day is really going to d____ me mad.

(2)My brother's favorite TV p____ is Running Man, but I like Animal World.

(3)The young man hoped to a____ his dream by working hard.

(4) It's polite for a young man to give his s ____ to the old on the bus.

(5)Our teacher gave us some v____advice on how to learn English well.

(6)Mom, one ____(调羹)of salt is enough for the soup.

(7)Cindy is very interested in Chinese ____ (历史).That's why she came to China.

(8)Our English teacher is very____ (严格的) with us.

(9)You need to ____ (检查)carefully for spelling mistakes after writing.

(10)Can you help me ____ (翻译)this English poem into Chinese?

    Bell was a British teacher to deaf people. He was born in Scotland in 1847 and went to school in London. Bell was interested in helping deaf people to learn to speak. He taught people how to use their mouths to make the sounds needed for talking.

    Bell's family moved to Canada in 1870 and to the USA in 1871. For several years he taught the people who could not speak in Boston. But at the same time he was developing a way to use electricity to send the sounds of talking along a wire, and he made the first telephone in June, 1875.

    The telephone developed quickly in the USA over the next few years. The Bell Telephone Company started in 1877, and in 1878 the first telephone centre was built in New York. More than 150,000 people had telephones in their homes ten years later. Bell was a kind man and spent much of his money and time during the rest of his life helping deaf people. In 1922 he died in Canada.