Complete the article. MACHU PICHU
We (16) …………………………………………. (know) about Machu Picchu for over a century now. Archaeologists (17) …………………………………………. (discover) this ancient Inca site in 1911. They (18) …………………………………………. (write) books and newspaper articles about their discovery, so people all over the world (19) …………………………………………. (read) about the site and (20) …………………………………………. (want) to see it for themselves. The first tourists (21) …………………………………………. (start) to arrive in the 1960s. Now, more than half a century later, millions of visitors (22) …………………………………………. (be) to Machu Picchu. Tourists from all over the world (23) …………………………………………. (see) this marvellous Inca city with their own eyes.
In recent years, Machu Picchu (24) …………………………………………. (become) one of the most popular tourist attractions in the world. Luxury’ hotels have been built not far from the site, while in the late 1990s, the Peruvian government (25) ………………………………………. (allow) the construction of a cable car for visitors. However, all this (26) …………………………………………. (do) a lot of harm to the site. It (27) …………………………………………. (pollute) the atmosphere and caused noise pollution around the ancient city. In an effort to protect the site, UNESCO (28) …………………………………………. (make) Machu Picchu a World Heritage site in 1983.