Complete the text with the Past Simple or Past Continuous forms of the verbs in brackets: It was a warm day. The sun (shine) and the birds (sing) in the sky. Suddenly, the explorers (hear) a strange noise in the forest. They (not know) what it was. So, what (they / do)? They (run) back to the car.

It was a warm day. The sun was shining and the birds were singing in the sky. Suddenly, the explorers heard a strange noise in the forest. They did not know what it was. So, what did they do? They ran back to the car.