Directions: In the following passage, there are some numbered blanks. Fill in the blanks by selecting the most appropriate word for each blank from the given options.

Many people have sacrificed their lives to (1) the thirst for knowledge and to satisfy their (2). In the olden days people used to worship sun and moon thinking them to be (3) celestial bodies. But the scientific investigation had 4) that sun is an ordinary star and earth is a planet like other planets. After this, man entered the age of the space travel. The invention of rocket was the first step in space travel. Scientists had already (5) that there was neither air nor water on the moon. The moon was the first (6) of man. A spaceship travelling at a speed of 4000 km per hour can (7) this distance in 10 hours. The scientists had (8) discovered that the surface of moon was rough and full of craters, rocks and mountains.

Fill in the blanks (8)