Question

use context to determine meaning. after many decades of human manipulation, english bulldogs are so far from their natural ancestors that they commonly suffer from abnormalities, such as small windpipes and closed nostrils. our efforts to breed so many of these dogs have diluted the bloodline, thinning and weakening it further with every generation. rather than creating a sustainable breed of dog, we have opted for an unsupportable dog breed that cannot be maintained for much longer. what type of context clue is used to determine the meaning of abnormalities? example complete. use context clues to define diluted. thinned out complete. use context clues to define sustainable. long - lasting recurring once per year self - maintaining

Explanation:

For "abnormalities", the phrase "such as small windpipes and closed nostrils" gives examples to clarify its meaning. For "diluted", the context "thinning and weakening it further" helps define it as "thinned out". For "sustainable", the contrast with "an unsupportable dog breed that cannot be maintained for much longer" implies it means long - lasting.

Answer:

Use context clues to define sustainable: long - lasting