This question asks the reader to choose the best alternative to correct the dangling modifier, which is a phrase that isn't attached to the rest of the sentence in a clear manner. Here, the phrase "one time a mystery" modifies the word "reasons." Therefore "reasons" must follow its modifier immediately. The only option choice that does this is "One time a mystery, the reasons behind the creation of the Stonehenge are now understood by scientists."

This original sentence contains a dangling modifier that needs to be corrected. The introductory clause "In order to achieve better results" is modifying the scientist's behavior, therefore the word "scientist" must immediately follow its modifier.

This question requires the reader to correct the dangling modifier. The phrase "While watching his favorite football team on TV" is modifying Ashton. Therefore "Ashton" must follow this phrase immediately. One answer is a bit deceiving: "While watching his favorite football team on TV, Ashton's focus was suddenly interrupted by a commercial." Though the name Ashton immediately follows the modifier, it's being used as a possessive modifier of the noun "focus," so technically "focus" still immediately follows this phrase. 

This question requires the reader to correct the dangling modifier. The phrase "When picking a puppy" is referring to someone who performs this action. Therefore we need a name or pronoun that refers to a person that will immediately follow this phrase. Every other choice has the wrong noun immediately following the modifying phrase. 

The dangling modifier "Overjoyed to have finally found a position in his field" describes the noun John and should therefore be followed by this noun. Amodifier should begin a sentence, is set off by a comma, and is followed by the noun(s) to which the modifier refers. If the subject of the main clause does not match up with the subject of the introductory clause that modifier is left hanging, which is fun for neither people or modifiers!

The dangling modifier "Celebrated for their loyalty and unwavering companionship" refers to "dogs," the  noun being described, but the subject of the main clause here is "man." Anytime you have an introductory clause that modifies a later noun, you should be careful to double-check that the modifier describes the grammatical subject of the main clause.

It is not the writing of James Martin that has published over 200 stories, it is James Martin himself, so the correct answer assigns the modifier to the correct subject.

Casey is the person who is preparing for the party, not her decorations. As it stands, the modifying phrase is misplaced so that the sentence is confusing and implies that Casey's decorations are doing the party preparations. The correct answer is the only one that correctly refers to Casey instead of her decorations as the person or thing performing the action in the sentence.

This question asks you to correct a dangling modifier, which occurs when it is unclear what phrase is being modified. In this sentence, the structure incorrectly suggests that the bottle itself drank the water. A modifying phrase should be placed as close as possible to the phrase it modifies, so the phrase "Having drunk all the water" should be placed next to the description of who drank it, "Bill."

Since Jerry's date "descended" the stairwell, it is obvious that she was not "looking up" Thus, "beginning" her descent as Jerry looked up at her is the correct modifying phrase for the anchor, "Jerry's date."