I)-Choose the word which has a different stress pattern from the others. 1. A. alien B. but C. because D. because of 2. A. exploration B. accommodate C. environment D. experience 3. A. forgetful B. wonderful C. beautiful D. waterless 4. A. sighting B. climate C. attempt D. system 5. A. astronaut B. Mercury C. Jupiter D. computer II)-Choose the best answer A, B, C or D to complete the sentences. 6. An astronaut has to wear a spacesuit ___________it may be very cold in space. A. so B. but C. because D. because of 7. The UFO landed on a ____________area. A. grass B. grassy C. grassed D. grassing 8. Scientists have been trying to find ___________ of aliens. A. amounts B. records C. traces D. sights 9. There have been many UFO _____________reported. A. sights B. signs C. signals D. sightings 10. Mars is called the Red Planet due to its ___________ surface. A. red B. redder C. reddest D. reddish 11. In the mid-19th century, scientists discovered that Mars had some similarities _____________ Earth. A. to B. with C. of D. from 12. Neptune is bright blue __________it is named after the Roman God of the sea. A. Because B. but C. So D. or 13. There is a lot of interest in doing experiments in the __________conditions. A. weigh B. weighing C. weight D. weightless 14. Titan, one of Saturn's ____________, has a thick atmosphere. A. satellite B. spaceships C. moons D. comets 15. Scientists believe that Mars also __________seasons just as the Earth does. A. spends B. experiences C. experiments D. takes