Australian Aborigines were the first people to live in Australia. There were once many, many different tribes of Aborigines, each with different traditions and languages.
Around 2% of the Australian population identifies as Aboriginal.
Acrophobia is the fear of heights. Most people are afraid of heights to some degree, especially when there is nothing to stop them from falling, like the cliff edge in the picture.
You are allergic to something if your body has a bad reaction to it. Allergic reactions can include getting a rash, sneezing, getting watery eyes or having difficulty breathing.
People are often allergic to dogs or cats, pollen or insect stings.
Ammunition relates to anything needed for firing a weapon, such as the supply of bullets and any other supplies like priming powder. Ammunition can also be used to describe spent parts of the ammunition after the weapon has been fired.
Anger is a strong feeling of displeasure. Another word for angry is mad. People often get angry when they don't get their way, or when someone disagrees with them. The person in the picture is angry.