The advantage of coming to the United States for high school early is that your English ability is much stronger than that obtained by preparing for TOEFL and SAT in China, which is more suitable for future undergraduate study. However, only from the perspective of preparation standards, domestic ones seem to be more efficient.
It is best to study in the United States from the tenth grade after finishing the first year of high school in China. The study pressure is not so great, which is conducive to the rapid improvement of English level.
American high school math and physics teacher