WHITE PHOSPHORUS, A SUBSTANCE _____ IN MATCHES, IS SO FLAMMABLE THAT IT BURST INTO FLAME UPON CONTACT WITH THE AIR

34. - DE THI THU NXB BO GD CO DAP AN
DE THI THU NXB BO GD CO DAP AN
34. White phosphorus, a substance _____ in matches, is so flammable that it burst into flame upon contact with the air. A. is common B. common C. which being common D. being common, is