判断背斜和向斜最可靠的依据是                            （   ）

A．岩层的弯曲形态

B．地形的起伏状况

C．岩层的坚硬程度

D．岩层的新老关系

The Puchalski Company reported the following:

A．

B．Year 1

C．Year 2

D．Year 3

E．Year 4

F．Income before taxes

G．$1000

H．$1000

I．$ 900

J．$ 800

K．Taxable income

L．$ 800

M．$ 900

N．$ 900

O．$1000