The list of objects that allows light to pass them all has one thing in common; they are transparent (clear). Clear items will enable the light to move without being blocked or absorbed. Sunscreen, walls, hats, and umbrellas all block light from passing through.

Based on the data given can conclude that some materials are transparent and let all light pass through. Some materials stop some light from passing through. Some materials are solid and block or reflect all light. A beam of light will have a different effect on an object based on that object's characteristics.

The worst item for blocking all light would be the glasses. Glasses allow all light to pass through unless they are coated or tinted like sunglasses to block light. A much better item to block light would be a show because it is made of a dense, solid material that does not allow light to pass.

The best item for blocking light would be the cardboard. Cardboard is a thick, dark material that would not allow light to pass through or be reflected. Cardboard is used for packaging because it not only hides what is inside and is sturdy, but it keeps light from damaging the items inside.

Sound comes from human-made and natural sources. An example of a human-made source would be a radio. An example of a natural source of sound would be a waterfall. The sound travels to our ears the same if it is human-made or natural.

Vibrations create sounds. When something vibrates, like a rubber band, a sound is produced. The vibrations create sound waves that travel to our ears for processing.

Of all of the examples calling 911 during an emergency and talking to an operator is a way of communicating using sounds and solving a problem. The other choices make a sound, but there is no problem being solved. Many times we need to communicate with people over a distance, so inventions like the telephone help solve this issue.

One of the old-fashioned ways kids would communicate over a distance before there were cell phones and computers was to make their phones! You could attach two paper cups to either end of a string and use them to talk into and listen. The sound is transmitted, and friends could use them to speak across a yard or bedroom. The other options allowed people to communicate over a distance but were not using sound.

The best plan based on the teacher's instructions would be Group 1's plan. They have replaced spoken language with a communication system based on sound. They have an idea of what each sound means and how it will be used. The other group is relying on head shakes and using the drum for celebrating, not communicating.

The best way for Sadie to test her design is to build it and use it. If she makes it and finds some things that need to be fixed or changed, she can work on her design. If she never actually builds it, she won't know if it works.