1A.an explosion
Dẫn chứng : An eruption can like an explosion
2D.All above
Dẫn chứng : Rock and lava can throw up into the air. Streams of red hot lava quickly run down from the peak of the volcano. The air is filled with deadly gases.
3B.Scientists
Dẫn chứng : Scientists have learned that there are many things that they can study to help them tell when an eruption might happen
4D. 4
Dẫn chứng : When a volcano is about to erupt, the ground will often move just like it does during an earthquake. Scientists can also measure the gases that come out of a volcano. Most volcanoes emit gases all of the time. More gases are let out as the volcano gets closer to erupting. They can also study the way the land and water around the volcano. Scientists can read these signs and warn people of danger. They may not realize it, but their work helps to keep people safe!
5A.the ground moves as it does during an earthquake.
Dẫn chứng : When a volcano is about to erupt, the ground will often move just like it does during an earthquake.