527
-DOCSTART- @SuperVikArya elevation of houston area ranges from 45 feet ( downtown ) to 20 feet ( clear lake ) to near zero at the coast .
 downtown, clear lake
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: exact location, area, road, river 
Text: {0} 
Answer:
 downtown, clear lake