• 
• A. 9
• B. 12
• C. 15
• D. 13

Answer: Option A

Explanation:

• A. $H_{2}S and C{O}_2$
• B. $Lima and H_{2}O$
• C. $CaS{O}_4 and H_{2}O$
• D. $C{O}_{s }and calcium$

Answer: Option C

Explanation:

• A. $4g/c{m}^2$
• B. $1g/c{m}^2$
• C. $6g/c{m}^2$
• D. $9g/c{m}^2$

Answer: Option B

Explanation:

• A. $CO$
• B. $C{O}_2$
• C. $S_{2}O$
• D. $CFC$

Answer: Option B

Explanation: