Submitted by admin on Wed, 10/28/2015 - 00:12
definition:
The process of becoming progressively worse:
sentence:
Industrial pollution is a major cause of deterioration of the environment
difficulty:
medium
toefl frequency:
3
toefl classification:
adverb:
adjective:
adverb sentence:
adjective sentence:
verb:
verb sentence:
noun:
noun sentence: