Here's the corrected passage with the appropriate answers:

The Amazon Rainforest

The world's largest tropical rainforest is the Amazon. Covering nearly 5.5 million square kilometres, the Amazon is so big it can contain the entire UK plus Ireland seventeen times! The Amazon is (1) **located** in South America and spans across several countries, including Brazil, Peru, Ecuador, Venezuela, and Colombia.

Moreover, the Amazon is home to an enormous (2) **number** of plants and animals, with nearly 40,000 plant species, 1300 kinds of birds, 430 mammals and millions of different species; there are many (3) **rare** species that cannot be found anywhere else, and deep in the forest, there are many more that haven't even been (4) **discovered**. It has attracted a lot of explorers and tourists from all over the world!

The Amazon rainforest is also home to 400 or 500 different groups of native tribes. These tribes spend most of their time living in the rainforest, and nearly fifty groups have never (5) **seen** the outside world!