真的有点难找的。歌曲名叫：Hips do not lie bamboo可在百度MP3中直接搜索该英文名。大小5.7M。标准欧洲原版。
答案是C，had begunBy the time he was twelve,Edison had begun to make a living by himself.By the time表明截至到某一段时间为止，后面的句子须用完成时态对应。
