4. The prepositional phrase in this sentence is "in an area", the subject is "The blast", and the verb is "flattened"
5. The prepositional phrases are "in Russia" and "to the remote region", the subject is "political events", and the verb is "delayed".
6. The prepositional phrase is "in 1927", the subject is "the first researchers", and the verb is "explored"
7. The prepositional phrases are "by the extent" and "of the devastation", the subject is "They", and the verb is "were amazed"
8. There are no prepositional phrases in this one, the subject is "no crater", and the verb is "was found"
9. The prepositional phrases are "of times" "than an atomic bomb", the subject is "scientists", and the verb is "estimated".
10. The prepositional phrases are "after exploring many theories", "about five or six miles", and "above the Earth", the subject is "most scientists", and the verb is "believe".
I hope this helps you out! :-)
