题目

圆的周长是和它半径相同的半圆的周长的2倍________（判断对错）． 答案：【答案】错误【解析】解：因为半径相同，2πr÷（πr+2r）= ．答：圆的周长是和它半径相同的半圆的周长的倍．所以答案是：错误． 阅读理解 　　The first Europeans came to America in 1492 with Christopher Columbus．Since that time people have come to America from all over the world, from Europe, Africa, and Asia, and they have brought their music with them．This mixing of people and music has created American music． 　　Music is a very important part of our lives．Music is for dancing, drinking, eating, loving and thinking．Some songs remind us of our childhood or youth．Others remind of the people we love．Many important occasions, like weddings and funerals have special music．Every nation has a national song like the American “The Star-Spangled Banner”．In the US, high schools and colleges have school songs, too． 　　Music is a part of the history of America．It expresses the problems and feelings of its people．As the years pass, the music grows and changes． 　　Modern science has also changed music．Inventions like records, radios, movies, electric instruments, tape recorders, and videos have changed the way we play and listen to music．They have helped to make music an important form of international communication． 　　American music, from the earliest folk songs to modern“pop”, is known around the world．Music is one of America’s most important exports．It brings the people of the world together．Even when people cannot understand the same language, they can share the same music．Many people learn and practice English by singing songs, understanding American music can help you understand American people．“Put a dime(10 cents)in the juke box(自动点唱机), baby．” Let’s listen to the music! (1) The article mainly tells us about ________． [　　] A． how American music developed B． when American music developed C． what American music is D． why American music is so popular (2) From the text we know that ________． [　　] A． American music has spread all over the world B． American music began in the 1550s C． American music is special D． American music has changed modern science in the US (3) The last paragraph probably means that ________． [　　] A． American music is very popular B． American music is not known by people all over the world C． Ameican music can help us understand American people, their history and culture D． American music is important in our lives