__________ is the study of the natural world.

Scientists ask __________ about the natural world and conduct __________ to answer their questions.

During free exploration, scientists __________.

When making systematic observations, scientists follow __________.

All types of scientific investigations include making __________ and collecting __________.

Scientists __________ the world around them by using their five senses. An observation is something you __________, __________, __________, __________, or __________.

Scientists compare the observations made by different groups using the same tools. When scientists follow the same steps and use the same tools, what they __________ should be similar. If the observations are different, then the scientists should try to find reasons for the differences.

Scientists ask each other, __________.

To answer the question "How do you know?" scientists should provide __________ to support their thinking.

Scientists are always investigating new ways to solve __________.