题目

阅读下面短文，根据上下文填入适当的词语，或使用括号中的词语的适当形式填空，并将答案填写在答题卡上标号为31-40的相应位置。 With the _____________ (develop) of industry, air pollution is getting more _________ more serious. In Beijing, many people suffer different kinds of illnesses because ________ air pollution. Air pollution is caused by the following ________[ reason]: about half ________ the problem is caused by vehicles. There are more and more cars, buses on the roads, and they give off poisonous gases. 25% of air pollution is caused某患者得了一种常染色体显性遗传病，其父母均为患者．该病基因显性纯合致死，其父母再生一个患病孩子为杂合子的概率为（　　） A、13B、12C、23D、1