SEVERAL ________ ARE KNOWN TO CAUSE CANCER TO DEVELOP.A. CHEMISTS B...

18. - TRAC NGHIEM ON THI TOT NGHIEDE CHNH SUA
TRAC NGHIEM ON THI TOT NGHIEDE CHNH SUA

18.

Several ________ are known to cause cancer to develop.

A. chemists

B. chemistry

C. chemical

D. chemicals