如图所示复用段环，A、B网元之间断纤时，请画出它们之间业务的流向图。

The primitive root of the pleasure of parenthood is two-fold. (46) On the one hand, there is the feeling of part of one’s own body externalized, prolonging its life beyond the death of the rest of one’s body, and possibly in its turn externalizing part of itself in the same fashion, and so securing the immortality of the germ plasma. On the other hand there is an intimate blend of power and tenderness. The new creature is helpless, and there is an impulse to supply its needs, an impulse which gratifies not only the parent’s love towards the child, but also the parent’s desire for power. (47) So long as the infant is felt to be helpless, the affection which is bestowed upon it does not feel unselfish, since it is in the nature of protection to a vulnerable portion of oneself.

(48) But from a very early age there comes to be a conflict between love of parental power and desire for the child’s good, for, while power over the child is to a certain extent decreed by the nature of things, it is nevertheless desirable that the child should as soon as possible learn to be independent in as many ways as possible, which is unpleasant to the power impulse in a parent. Some parents never become conscious of this conflict, and remain tyrants until the children are in a position to rebel. Others, however, become conscious of it, and thus find themselves a prey to conflicting emotions. In this conflict their parental happiness is lost. (49) After all the care that they have bestowed on the child, they find to their mortification that he turns out quite different from what they had hoped. They wanted him to be a soldier, and they find him a pacifist, or, like Tolstoy, they wanted him to be a pacifist, and he joins the Black Hundreds.

But it is not only in these later developments that the difficulty is felt. (50) If you feed an infant who is already capable of feeding himself, you are putting love of power before the child’s welfare, although it seems to you that you are only been kind in saving him trouble. If you make him too vividly aware of dangers, you are probably actuated by a desire to keep him dependent upon you. If you give him demonstrative affection to which you expect a response, you are probably endeavoring to grapple him to you by means of his emotions. In a thousand ways, great and small, the possessive impulse of parents will lead them astray, unless they are very watchful or very pure in heart.

(47) So long as the infant is felt to be helpless, the affection which is bestowed upon it does not feel unselfish, since it is in the nature of protection to a vulnerable portion of oneself.

根据FIDIC《施工合同条件》，为了不损害承包商的合法利益，关于指定分包商的说法，正确的有（）。

A.指定分包商的工作内容由工程师和承包商协商确定

B.承包商对指定分包商的违约不承担责任

C.给指定分包商支付工程款不从承包商的中标价中支出

D.承包商对指定分包商的施工协调收取相应的管理费

E.招标文件中已说明指定分包商的工作内容

斗鸡游戏起源于何时？

下列有关DNA和mRNA的描述中正确的是（）。

A.mRNA易被水解，DNA则较稳定

B.DNA可以配对形成双链结构，而mRNA则不能

C.在一定条件下，DNA和mRNA都可以形成双链结构

D.细菌的mRNA与其DNA一样稳定

热继电器的感应元件是（）。

A.电磁机构

B.易熔元件

C.双金属片

D.控制触头