Name 2 pieces of evidence about sea-floor spreading.

Rocks near mid-ocean ridge are younger than rocks near trenches and earth quake data shows ocean crust is sinking on to the mantle at trenches 

Eruptions of molten material and magnetic strips in the rock of the ocean floor.

Answer your driving test ;

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.