单项选择题
Structural traps are traps（）are formed because of a deformation in the rock layer （）contains the hydrocarbons.
A.that, that B.what,what C.what,that D.that,what
单项选择题 he oil（）in a source bed, and a marine shale.
单项选择题 Eventually chemical changes（）the generation of petroleum.
单项选择题 As time goes on the organic material is buried deeper and hence（）higher temperatures and pressures.
