單字：

matter (物體), gas (氣體), liquid (液體), solid (固體), steam (蒸汽),

breath (呼吸), smoke (煙), exhaust (排氣), ice (冰), log (木頭)。

句子：

1.What is a solid ? (A solid is form of matter that has its own size and shape.)

2.What is a liquid ? (A liquid is form of matter that takes the shape of its container.)

3.What is a gas ? (A gas is form of matter that has no shape and is hard to see.)