A. are B. is C. is being D. am
A. is B. am C. are D. were
A. have allowed B. allow C. allowing D. allows
A. is B. was C. are D. were
A. are polluted B. pollutes C. is polluted D. pollute
A. are B. is C. being D. be
A. is searching B. are searching C. searches D. search