【彭文俊】評論
What happened to the lava in the open air?第三段中Out of the cone came hot melted rock. This melted rock was lava. It moved like a river. It ran down the sides of the cone. It covered more and more of the land. Soon it covered the town of Paricutin. In the open air, the lava became cold and hard.故選(B) In the open air, the lava became cold and hard.