9-16. electricity.

[X is electricity.] = X is something you cannot see, but it is not gas. X is something that can move through long pieces of metal. People can use X to cause something to become hot, or to cause something to move, or to cause there to be light. People make long narrow thin pieces of metal that they can cause X to move through. When people cause X to move through very long metal pieces, X can move very far to other places where people can use it.

[This machine uses electricity to make it move.]

[Electricity is used to make light inside most buildings.]

9-17. blood.

[X is some blood.] = X is the red liquid that moves inside the bodies of living people and animals.

[Something cut my hand and caused some blood to move out of my body.]

9-18. amount, amounts, amount of, amounts of.

[The amount of X in one place is more than the amount of X in the other place.] = X is something you can compare or measure or count. There is some X in one place, and there is less in the other place.

[Each of these containers can hold the same amount of water.]

[The amount of money you gave me is less than what you promised.]

When __________ moves through these long narrow pieces of metal, this thing makes light.

• an amount of water
• electricity
• some blood