7 Sugar when burned becomes black. It turned into
A Useful B harmful
C. bemutiful
8. Which of these materials are useful?
A Detergent soap
c. bath soap
B Baby soap
D. all of the above
9. Which of these materials are harmful?
A Firecracker
Crust iron
B. Insecticides
D. all of the above
10. Improper disposal of waste materials like empty bottles. pampers, cigarette
butts are strictly prohibited because it is
A. Useful B. harmful C. beautiful D none of the above​