fical primers ?A. gold B. silver C. copper D. zinc

1- IF the tensile strength of a wood, used for a 10 year bridge, is determined to be 1500 psi , what is the tensile strength used for designing a 50 year bridge , considering the load duration factor ?A. 1350psi B. 1260 psi C. 1500psi D. 1950psi2- if the highest and lowest pavment temrpatures for design are determined to be 63 and -22 celsius respectively. please choose the asphalt binder for the pavemnet based on the performace grades.A. PG 63-22 B. PG64-22 C. PG63-23 D. PG 64-233- For a certain aggregate , if the passing percentage for US No. 30 sieve is 54% , what is the retaining percentage for US No. 30 sieve ?A. 100% B. 54% C. 46% D. 36%4- For steel corrosion protection , shich of the following can be as a sacrifical primers ?A. gold B. silver C. copper D. zinc