在我国，中央政府与地方政府之间的权力关系主要体现在（）.A.行 * * 和司法权 B.立法

商业折扣是为了鼓励客户尽早付款而给予的优惠。 ( )

极低密度脂蛋白中含量最多的成分是（）。

A.甘油三酯

B.胆固醇

C.载脂蛋白质

D.磷脂

E.游离脂肪酸

某公司预计的年度赊销收入为6000万元，信用条件是（2／10，1／20，n／60），其变动成本率为65％，资金成本率为8％，收账费用为70万元，坏账损失率为4％。预计占赊销额70％的客户会利用2％的现金折扣，占赊销额10％的客户利用1％的现金折扣。一年按360天计算。要求：

计算平均收现期。

The similarity between ichthyosaurs and fish is an example of convergence, a process by which different classes of organisms adapt to the same environment by independently developing one or more similar external body features. Ichthyosaurs were marine reptiles and thus do not belong to the same class of organisms as fish. However, ichthyosaurs adapted to their marine environment by converging on external body features similar to those of fish. Most strikingly ichthyosaurs, like fish, had fins.
If the statements above are true, which one of the following is an inference that can be properly drawn on the basis of them

A．The members of a single class of organisms that inhabit the same environment must be identical in all their external body features.

B．The members of a singly class of organisms must exhibit one or more similar external body features that differentiate that class from all other classes of organisms.

C．It is only as a result of adaptation to similar environments that one class of organisms develops external body features similar to those of another class of organisms.

D．An organism does not necessarily belong to a class simply because the organism has one or more external body features similar to those of members of that class.

E．(E) Whenever two classes of organisms share the same environment, members of one class will differ from members of the other class in several external body features.

原油性质变轻，初顶温度控制不变，则初顶（）。

A、干点升高

B、干点降低

C、初馏点降低

D、初馏点升高