如图甲，S点为振源，P点距s的距离为 r，t=0时刻S点由平衡位置开始振动，产生沿直线向右传播的简谐横波，图乙为P点从t₁时刻开始振动的振动图象，则以下说法正确的是（　　）

A．t=0时刻振源S的振动方向沿y轴负方向

B．t₂时刻P点振动速度最大，方向沿y轴负方向

C．该简谐波的波长为

D．该波与另一频率为

Divorce is the act by which a valid marriage is dissolved, usually freeing the parties to remarry. In regions in (1) ancient (2) authority still predominates, divorce may be (3) and rare, especially when, as among Roman Catholics and Hindus, the religious (4) views marriage (5) indissoluble. Custom, (6) , may make divorce a simple matter in (7) societies. (8) some Pueblo Indian tribes a woman could divorce her husband (9) leaving his moccasins on the doorstep. The (10) of individual determination and mutual (11) are making divorce (12) acceptable in the (13) parts of the world.

Among premodern societies, the rate of marital stability is difficult to (14) (15) the varying definitions of (16) and divorce. It seems to be broadly true (17) wherever divorce is a legal impossibility the wedding is a well-defined event conducted with (18) formality. The (19) principle does not hold true: elaborate marriage ceremonial is quite compatible with high divorce rates. Many anthropologists agree that divorce is generally more permissible in matrilineal societies (20) in patrilineal ones, in which the procreative and sexual rights of the bride are often symbolically transferred to the husband with the payment of bride-price.

3（）

A.easy

B.pleased

C.worse

D.difficult