2) The amount of rubbish should (be reducing/be reduced/been reduce)
3) If we don’t stop polluting the environment, another ecological catastrophe (will going to happen/will be happen/is going to happen)

1) has caused

2)be reduced

3)is going to happen

1)

Human activity has caused  a lot of environmental disasters around the world.

2)

The amount of rubbish should be redused

3)

If we don’t stop polluting the environment, another ecological catastrophe is going to happen

Объяснение: