题干

抗维生素D佝偻病为X染色体显性遗传病,短指为常染色体显性遗传病,红绿色盲为X染色体隐性遗传病,白化病为常染色体隐性遗传病,下列关于这四种遗传病遗传特征的叙述,正确的是(  )

A:短指的发病率男性高于女性

B:红绿色盲女性患者的父亲是该病的患者

C:抗维生素D佝偻病的发病率男性高于女性

D:白化病通常会在一个家系的几代人中连续出现

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B

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    One student took a box of chicken to class. Another carried on a cell-phone1and still another whistled loudly every time the2turned his back. Reform school? No. College.

    More and more, professors say, they are3 across rude students in their classrooms. Many of today's young scholars arrive late, leave4talk loud or take care of personal 5such as paying bills during class.

    Why are the students behaving badly?  “Because they can,” said a student of University of North Texas. “A lot of the time, the professors 6them get away with it.”

    Some educators say it is time to bring politeness back to their classrooms—and even7taking some of the blame for bad behavior. They say that8 students are by no means the majority but that one of them can ruin an entire9

    People are10when they learn that impolite behavior is becoming more and more common in11education, says Dr. Gerald Amanda, a counselor at City College of San Francisco. They12some high school students to misbehave but think those who get to 13 will behave more politely.

    Dr. Amanda believes that society in 14 has become more tolerant of rude behavior 15 that people in power, including professors, no longer 16 standards for politeness. That leads to a growing imprudence among some college17“There's a great18 of bad behavior in the world around them, and young people see it and19 disrespect,” said Dr. Amanda20that sometimes students have no idea that they are being rude.