Only the children interested went to the natural history museum to see the dinosaur exhibition. All but one of them was well behaved. A. Only the children interested went to the natural history museum to see the dinosaur exhibition. All but one of them was well behaved. B. Only the interested children went to the natural history museum to see the dinosaur exhibition. All but one of them was behaved well. C. Only the children interested went to the natural history museum to see the dinosaur exhibition. All but one of them was behaved. D. Only the interested children went to the natural history museum to see the dinosaur exhibition. All but one of them was behaved. E. Only the children interested went to the natural history museum to see the dinosaur exhibition. All but one of them was behaved well.

When tackling GMAT sentence correction questions, it's crucial to identify the correct grammatical structure that conveys the intended meaning clearly. For instance, consider the sentence about the children going to the natural history museum. Several options were presented, but only a few had the proper structure. Here's a breakdown of why certain options were correct while others were not.

- Option C and D were incorrect because 'was behaved' is not a proper English phrase.
- Option E was also incorrect due to improper word order 'behaved well' for this context.

Options A and B remained. While both are grammatically correct, Option A ('well-behaved') is more commonly used and reads more smoothly in context. This example shows the importance of not only choosing a grammatically correct option but also the one that is standard and flows well within the sentence.

Understanding basic grammar rules is essential for sentence correction. Take the following rules into account:

- **Subject-Verb Agreement**: Make sure that the subject and verb in a sentence agree in number. In the example, 'All but one of them was well behaved,' 'them' refers to children, but we talk about 'one,' so 'was' agrees with 'one'.
- **Word Order**: English sentences typically follow a Subject-Verb-Object order. Therefore, using 'well-behaved' as an adjective before the noun is more straightforward and standard.
- **Modifiers**: Placement of modifiers can change the meaning of a sentence. 'Only the interested children' emphasizes a specific group of children, which is clearer than 'Only the children interested'.

Applying these rules helps ensure that sentences are not only grammatically correct but also clear and concise. For example, placing the adjective 'interested' before 'children' as in Option A addresses these grammar rules effectively.

Using expressions that are standard in English will make sentences sound natural and easily understandable. During GMAT sentence corrections, you should consider how the sentence would be used in everyday language.

- **Well-behaved vs. Behaved Well**: Both phrases make sense grammatically, but 'well-behaved' is a more common adjective phrase for describing someone's behavior.
- **Natural Flow**: The choice between 'well-behaved' and 'behaved well' can also influence the flow of the sentence. 'All but one of them was well-behaved' feels more natural compared to 'All but one of them was behaved well'.
- **Idiom Usage**: Familiarity with idioms and commonly used phrases makes it easier to pick the correct answer in sentence correction problems. 'Well-behaved' is an idiomatic expression, which means it is recognized and used frequently in English.

Therefore, while both Option A and B are correct, Option A is preferred due to its standard usage in everyday language. This makes it align with how native speakers commonly express themselves, which is key for mastering GMAT grammar questions.