29. New ways _____ to prevent the river _____.

A. have found out, from polluting

B. have found, from being polluted

C. have been found out, from being polluted

D. have been found, from being polluted

New ways _____ to prevent the river _____.

A. have found out, from polluting

B. have found, from being polluted

C. have been found out, from being polluted

D. have been found, from being polluted

29. New ways _____ to prevent the river _____.

A. have found out, from polluting

B. have found, from being polluted

C. have been found out, from being polluted

D. have been found, from being polluted

New ways _____ to prevent the river _____.