II. Complete the sentences with the words in the box. portable device submarines imitates patents observed inventions charge researching inspiration collapse versatile economical 1. The computer is definitely one of the greatest ______in the world. 2. People often use the natural world as ______for their inventions. 3. ______are very useful for scientists to learn about the undersea world. 4. Velcro, a hook-and-loop fastener, was invented after an engineer ______how the seeds of a plant clung to his clothing. 5. This dictionary is ______.You can take it with you. 6. A portable solar charger is used to______ mobile devices such as smart phones cameras, and laptops. 7. A flying car is just bit bigger than a normal car. So when its wings ________it fits quite well in any garages. 8. A laptop is very________, as it can do many things. 9. In 1999 and 2003, he obtained Thai ________for his rain-making techniques. 10. A laptop is ________so we don't have to spend much money. 11. The submarine, which can travel underwater, ______a dolphin's shape. 12. I use my computer for______ topics on the Web and typing my assignments as well.