According to the inverted triangle structure, which function does Sentence (3) have?(1)The definition of higher education may vary depending upon the laws and culture of the country involved.(2)In the United States, higher education is considered to be voluntary studies beyond the high school level. This is the same with the higher education system in China. However, the two countries also differ in aspects such as admission system, student life and evaluation system.(3)This article focuses on some of the significant differences and discusses them in detail.