A GAS OR OTHER SUBSTANCE WHICH IS SENT OUT INTO THE AIR IS _______

33. - File thứ 5: de_va_dap_an_45_phut_so_3_lop_11_sach_moi_311201817
File thứ 5: de_va_dap_an_45_phut_so_3_lop_11_sach_moi_311201817

33. A gas or other substance which is sent out into the air is _______.

A. disease B. emission C. carbon footprint D. greenhouse gas

Choose the letter A,B,C or D that need correction