Expand the sentences. Use if or when.

1.

When winter comes, days get shorter.

2.

If you heat metal, it will expand.

3.

If iron gets wet, it will rust.

4.

If you do not water the plants, they will die.

5.

When you heat water to 100°, it will boil.

6.

If you drop ice on water, it will float.

7.

When you come, we can talk about it.

8.

When they meet, they discuss all details.