题干

对下列各图所表示的生物学意义的描述,正确的是(    )

A:甲图中生物自交后产生基因型为Aadd个体的概率为1/6

B:乙图细胞一定是处于有丝分裂后期,该生物正常体细胞的染色体数为8条

C:丙图家系中男性患者明显多于女性患者,该病最有可能是伴X隐性遗传病

D:丁图表示某果蝇染色体组成,其配子基因型有AXW、axW、AY、aY四种

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D

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    When I was a little kid, one of my favorite things to do was going to the zoo. I have recently heard that there are debates as to whether elephants should live in zoos or should they wander around free. My position is that elephants should live in zoos for people to see.

    Many experts say that elephants have a good life living in zoos. There are 78 zoos that exhibit elephants. Most zoos are taking the necessary steps to make living conditions better for the elephants. They are doing things such as replacing hard floors with sand or dirt. This makes it easier for them to wander around. Zoos are also expanding their elephant house to give the large animals more room to go around.

    Zoos also protect endangered species. According to the World Wildlife Fund, in 2014 the total population of African elephants was around 700,000, and the Asian elephant population was around 32,000. The Asian elephants are on a path to dying out. Without zoos, they all are likely to disappear within our lifetime. The National Zoo plans to spend millions of dollars on a new Asian elephant habitat. That way, they can start their own group if the Asian elephants are gone.

    There are people who want zoos to empty all of their elephant displays. If they decide to do so, it would take the chance to see elephants up close away from people. That could change the public's favorable opinion of elephants. National Zoo director John Berry says that allowing visitors to experience the elephants up close encourages people to care about endangered species.  During one of my visits to the zoo, it was a very hot day. I was sweating a lot. Big Ben, the largest elephant on display, walked up to me and gently squirted(喷) my face with water from his trunk. Everyone was amazed at what he did. That was a very nice thing for Big Ben to do. I am sure that elephants are the nicest animals on earth. I wish all zoos would keep their elephant displays open to the public. I want all my friends to be able to experience what I did with Big Ben.

    I feel zoos should follow all the necessary steps to keep elephants in zoos. I would raise money at my school if I thought it would help to keep elephants in zoos.