retaining wall

breast wall

parapet wall

none of the above

only on the hill side of road

only on the opposite side of hill

on both sides of road

none of the above

length

weight

cross-section

weight per unit length

carbon and silicon

manganese and phosphorous

carbon and manganese

carbon and sulfur

12 m and 12 m

12 m and 13 m

13 m and 12 m

13 m and 13 m