第31题: [单项选择]The old lady has developed a ______ cough which cannot be cured completely in a short time. A. perpetual B. permanent C. chronic D. sustained 参考答案:C 答案解析:[考点] 考查形容词词义辨析。 perpetual意为“永久的”;permanent意为“长期的”;chronic意为“慢性的”;sustained意为“持续不变的”。结合句中的cannot