Read and complete the following passage, using the words in the box.

destructive         ; problems        ; their ;         to ;            erupts

When a volcano (1) _______, hot gases and melted rock from deep within Earth find (2)________ way up to the surface. This material may follow slowly out of a crack in the ground, or it may explode suddenly into the air. Volcanic eruptions may be very (3) _______. But they can also create new landforms. Of the nearly 1,900 volcanoes active today, or known to have been active in historical times, about ninety percent can be found in the areas of South America, North America, Asia, and Oceania that are close (4) _______ the Pacific Ocean