1 In 1957, a dog (become) the first animal to orbit the Earth.
2 In 1969, two astronauts (land) on the moon.
3 While they (walk) on the moon, another astronaut stayed on another craft orbiting the moon.
4 My grandad was listening to the radio when he (hear) the news.
5 My grandma (read) a book when my grandad told her.
6 The three astronauts (return) to Earth three days later.