28. The Betaken house Ruins at Navajo Monument is among the largest and most elaborate cliff dwellings in the country.

29. The island of Kauai has much streams, some of which have worn deep canyone into the rock.

30. It's a common observation that liquids will soak through some materials but not throught other.

The sentences you've provided seem to focus on grammar and usage in English, specifically with issues regarding singular/plural noun agreement and word choice.

Sentence Analysis for Sentence 28:
- Sentence: "The Betaken house Ruins at Navajo Monument is among the largest and most elaborate cliff dwellings in the country."
- Correction: The sentence should say "Betatakin Ruins at Navajo Monument are among the largest and most elaborate cliff dwellings in the country."
- Explanation: "Betatakin Ruins" refers to a proper noun of a specific location. The verb "are" is used for the plural subject "Ruins."
Sentence Analysis for Sentence 29:
- Sentence: "The island of Kauai has much streams, some of which have worn deep canyone into the rock."
- Correction: "The island of Kauai has many streams, some of which have worn deep canyons into the rock."
- Explanation: The word "many" is the correct quantifier to use with the plural noun "streams." Additionally, "canyone" appears to be a typo and should be "canyons," the correct plural form of "canyon."
Sentence Analysis for Sentence 30:
- Sentence: "It's a common observation that liquids will soak through some materials but not throught other."
- Correction: "It's a common observation that liquids will soak through some materials but not through others."
- Explanation: "Through" is the correct spelling, and "others" is the proper plural noun form needed here, which refers to "other materials."