A. lead or concrete
B. lead and tin
C. graphite or cadmium
D. thick galvanised sheets
E. black carbon papers
Correct Answer: lead or concrete ✔
Last Updated: January 24, 2019
A. lead or concrete
B. lead and tin
C. graphite or cadmium
D. thick galvanised sheets
E. black carbon papers
Correct Answer: lead or concrete ✔
Last Updated: January 24, 2019