"The Governor-General is the representative of the Head of State in Australia. They perform a range of constitutional and ceremonial duties, acting on the advice of the Prime Minister and the Federal Executive Council."
Australian Citizenship Test gives you access to many more tests than just the one practice test available on the government website. That official sample test is good for giving you an idea of what to expect on the real test. But it can't help you prepare fully. Nor does reading the Australian Citizenship: Our Bond material alone.