题目内容
Phil is a scientist for NASA. Scientists are always asking questions. One question Phil has is:”Are Rocks on the Earth l1. rocks on Mars?” The first step was to collect rocks from around the world. I2. of collecting the rocks himself, Phil thought of a good idea. He would ask kids everywhere to s3. him rocks. Soon children from all over the world have sent in over 8,000 rocks. Phil and other scientists study each rock to d4. what minerals(矿物质) are in it. Studying rocks from the Earth is the easier part of Phil’s project. Learning about rocks on Mars is more c5.. To do this, Phil helped c6. a special camera that was sent into space. It c7. around Mars and takes pictures of rocks there. Scientists learn a lot by c8. rocks from the Earth and Mars. They learn how the Earth and Mars are d9., and they learn how the planets are alike, too.
Mars is the planet most like Earth. “ Studying Mars can tell us a lot about the planet and what humans have to be p10. for when they get there,” Phil said.
