请以“蓝图”为题，写一篇文章。要求：(1)参考给定资料，观点鲜明，内容充实，结构完整

下列关于波的干涉、衍射及多普勒效应的说法正确的是[ ]

A．机械波的波长越短、障碍物或孔的尺寸越大，衍射现象越明显

B．出现稳定的干涉现象时，振动加强点始终位于波峰或波谷

C．出现稳定的干涉现象时，振动加强点某时刻的位移可能为零

D．当波源和观察者靠近时，波源频率不变，观察者接收到的频率减小

含丰富维生素C的水果是（）。

A.苹果

B.桃

C.鲜枣

D.柑橘

E.草莓

下列物质中，（）属于纯净物。

A．二氧化碳

B．空气

C．水

D．铁

Charles Darwin wed his cousin Emma and spawned 10 children, including four brilliant scientists. Albert Einstein’s second wife Elsa was his first cousin. Queen Victoria said “I do” to hers. So have millions worldwide. In parts of Saudi Arabia, 39% of all marriages are between first cousins.

In the U. S., though, the practice bears a stigma of inbreeding just this side of incest. The taboo is not only social hut legislative; 24 states ban the marriage of first cousins: five others allow it only if the couple is unable to bear children. A major reason for this ban is the belief that kids of first cousins are tragically susceptible to serious congenital illnesses.

That view may have to change. A comprehensive study published recently in the Journal of Genetic Counseling indicates such children run an only slightly higher risk of significant genetic disorders like congenital heart defects — about two percentage points above the average 3% to 4%. Says the study’s lead author, Robin Bennett, president-elect of the National Society of Genetic Counselors, which funded the study: “Aside from a thorough medical family history, there is no need to offer any genetic testing on the basis of consanguinity alone”.

Publication of the study will do more than tweak public awareness; it will enlighten doctors who have urged cousin couples not to have children. “Just this week,” says Bennett, “I saw a 23-year-old woman who had had a tubal ligation because her parents were cousins and her doctor told her she shouldn’t have children.”

The American proscription against cousin marriages grew in the 19^th century as wilderness settlers tried to distinguish themselves from the “savage” Indians, says Martin, author of the book Forbidden Relatives: The American Myth of Cousin Marriage. “The truth is that Europeans were marrying their cousins and Native Americans were not.”

And doesn’t God have stern words on the subject Christie Smith, 37, a Nevada writer, says she felt guilty when she fell in love with her first cousin’s son Mark. “I was trying so hard to convince myself not to have these feelings,” she recalls, “that I went to the Bible looking for confirmation that it was wrong. And what I found was the exact opposite: support for cousin marriages.” The patriarch Jacob married two of his first cousins, Rachel and Leah. Smith married Mark in 1999.

The medical ban is lifted; the social stain may take longer to disappear.

It is suggested in Paragraph 1 and 2 that the cousin marriage（）

A. resembles incest in nature

B. puts cousin couples to shame

C. always causes serious genetic disorders

D. is a common phenomenon across the world

问题：请根据所学法律知识，对本案进行全面分析。