第24题: [单项选择]男孩,3岁。生后5个月见体格发育落后,表情呆滞,伴有点头、弯腰样发作,每日约10余次。2岁开始出现呕吐,喂养困难。现体检见小儿智力明显落后,毛发棕黄色,肤色浅,尿无明显霉臭味,尿三氯化铁试验出现绿色。脑电图示高峰节律紊乱。上述患儿如为非经典型苯丙酮尿症,其发生的最主要机制是() A. 二氢生物喋呤还原酶先天缺乏 B. 高苯丙氨酸血症 C. 酪氨羟化酶被抑制制 D. 血酪氨酸浓度下降 E. 四氢生物喋呤生成不足 参考答案:E
第25题: [单项选择]地面水中有机物污染较重时,会引起 A. 溶解氧含量增加 B. 生化需氧量降低 C. 化学耗氧量降低 D. 溶解氧量降低 E. 有机碳降低 参考答案:D
第27题: [单项选择]How big is the house he moved in
a. As big as the old one.
b. Twice as big as mine.
c. As big as mine.
d. Twice bigger than mine. 参考答案:B 答案解析:[听力原文]
Since he moved out of the old apartment, he has lived in a house twice as big as mine.
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