1. VOCABULARY EXPEDITION 3 LESSON 1 ancient The walls of the ancient building were crumbling and in ruins. very old; from the distant past develop Inventors develop new sneaker materials that make shoes lighter and more comfortable. to bring into being position Ruth was careful to position the pizza in the middle of the table so that everyone could reach it. the place where something is astronauts The astronauts looked out of the spacecraft window and saw the small, blue Earth far below. someone trained to travel and work in space astronomy Nikko took a course in astronomy, because he was interested in learning about the planets and stars. the scientific study of stars

2. VOCABULARY EXPEDITION 3 LESSON 3 surface The surface of a tennis ball is fuzzy. the outside part of something vast The Pacific Ocean is vast. very, very large unit An inch is a unit of measurement. a standard amount by which things are measure orbit The moon follows an orbit around the Earth. the path one object takes as it moves around another organized The clothes in a local store display are organized by color. grouped together

3. VOCABULARY EXPEDITION 3 LESSON 6 exist When we read nonfiction, we read about things that exist, such as real people and things. to be alive or real direct The family took a direct route to the campground, without any of the usual side trips. simple and straightforward intelligence The apes showed a sign of intelligence when they used a stick as a tool to get food. the ability to learn skills and facts, and to apply them in some way watery The visitors felt uncomfortable because they were not used to the humid, watery swamp. having the quality of water bacteria To avoid spreading bacteria, always cover your mouth when you cough. a very small life form; germ

4. VOCABULARY EXPEDITION 3 LESSON 8 artificial The artificial flowers were made of silk and plastic. made by humans communication The communication tools we use today connect people more quickly than did older methods, such as letter writing. having to do with sending or exchanging information system A system of computers and satellites is used to predict the weather. a set of things acting together accurate The forecast of rain proved to be accurate when the thunderstorm struck the city. correct