岩石按成因分为()、()、()三大类。
参考答案:火成岩;沉积岩;变质岩
将两个物体放在水平桌面上,它们的重力之比是1:3,两个物体与水平桌面的接触面之比2:1,则两物体对桌面的压强之比是:[ ]
A.1:3
B.1:2
C.1:6
D.6:1
The way in which () wrote "The Scarlet Letter" suggests that American Romanticism adapted itself to American puritan moralism.