1. It's a bit difficult to get into Harvard University for postgraduate entrance examination. At least you need high GT scores and undergraduate grades, as well as a good educational background and other highlights such as scientific research and social practice.

2. It is relatively easier to apply for a prestigious school in Australia and Canada, such as the University of Toronto, than to apply for a prestigious school in the United States. Details can be found in official website.

3, the difficulty is relative, if all aspects are excellent, it is not difficult, otherwise it may not be admitted to the top schools in the United States.