Sometimes fire is our friend. I can help us in many ways. But sometimes it is our enemy. It can be very harmful. Big fire can burn trees, houses, animals, or people.
有时火是我们的朋友，它可以在许多方面帮助我们。可是有些时候它又是我们的敌人，它可能伤害我们。一场大火可能烧掉树木和房屋，动物，甚至烧死人。

Now we can make a fire easily with matches or lighters. Some children like to play with them, but matches and lighters can be very dangerous.
如今我们能用火柴或打火机轻易地点火。有些孩子喜欢玩火柴或者打火机，可是它们是很危险的。

One match can burn a piece of paper, and then it could burn a house. A small fire can turn a big fire quickly.
一根火柴可以点燃一张纸，然后可能烧毁一座房子。一场小火可以很快变成一场大火。

Be careful with fire, and it will help us. But if we aren't careful with it, it may hurt us.
如果我们对火小心点，它会帮我们忙。如果我们不小心，它会伤害我们。

词义解析：

1.sometimes：有时候
2.enemy：敌人
3.harmful：有害的
4.match：火柴
5.lighter：打火机
6.dangerous：危险的
7.burn：燃烧
8.hurt：伤害