Dark clouds may sweep_across the ground.Logical formLearned from5 sentences. Clouds of war may darken.Logical formLearned from5 sentences. Clouds may be associated with a cold front.Logical formLearned from5 sentences. An increase can be in clouds.Logical formLearned from5 sentences. (Jet fighters) may roar above clouds.Logical formLearned from5 sentences. Clouds of steam may rise to a height of some meters.Logical formLearned from5 sentences. (Health risks) may be posed by clouds of smogs.Logical formLearned from5 sentences. Clouds can be constituted-of-or-filled-with smogs.Logical formLearned from5 sentences. Wildfires may create a cloud of smog.Logical formLearned from5 sentences. Concerns may cast a dark cloud.Logical formLearned from5 sentences. (Rain clouds) may open on a parade.Logical formLearned from5 sentences. An eye can be on gathering dark clouds.Logical formLearned from5 sentences. Dark clouds may gather over a male.Logical formLearned from5 sentences. A city may belch_out clouds of black smoke.Logical formLearned from5 sentences. A section may pertain-to an (ash cloud).Logical formLearned from5 sentences.