It is best to say that the protection to properties offered by sea walls along coasts _______.

To fill in the blank in the statement about the protection offered by sea walls along coasts, we need a word or phrase that accurately reflects the effectiveness and limitations of sea walls in coastal protection.

Analysis

1. Understanding Sea Walls: Sea walls are structures designed to absorb and reflect the energy of waves to protect coastal areas from erosion and flooding.
2. Efficacy: While they can be effective, they often provide limited protection in extreme weather conditions and can lead to increased erosion at their base or adjacent areas.
3. Common Phrases: Phrases such as "can be effective but are not foolproof," "are helpful but have limitations," or "provide temporary relief" could complete the sentence meaningfully.

Suggested Completion

“It is best to say that the protection to properties offered by sea walls along coasts can be effective but has limitations.”