如果等腰三角形的底角为50°，那么它的顶角为（　　）

地图的三要素被称为地图的“语言”，下列哪一项是（　　）

小王同学特别喜欢地理，他准备按照人教版初一地理教材上册第5页的步骤，自制地球仪，他准备好了乒乓球、铁丝、胶布和橡皮泥。他先在乒乓球的中间用红笔画了一个圈（即下图中到点a和点b距离相等的圆圈），则小王同学是想用该线圈表示（    ）

阅读理解

　　Lang Lang is a famous Chinese pianist. He was born in 1982 in Shenyang. He showed his talent(天赋)for playing the piano when he was two. He began to take piano lessons at the age of 3. At the age of 5, he won the Shenyang Piano Competition. When he was 11, he won the first prize at the Fourth International Young Pianists Competition.

    He began his study at Curtis Institute(学院)in America when he was 15. He became the first Chinese student at the institute. During his study there he made great progress and became a top pianist. On August 14th, 1999, the great Andre Watts was ill so Lang Lang played at concert instead of him and he was successful. Then he became famous all over the world.

    In August of 2008, more than 5 billion people watched Lang Lang's performance at the opening ceremony(开幕式)of the Beijing Olympic Games. He also played at the opening ceremony of the Shanghai Expo(世博会).