The duties of a policeman are than . A. dangerouser ; a teacherB. more dangerous ; a tea

The duties of a policeman are than .
A. dangerouser ; a teacher
B. more dangerous ; a teacher
C. greater danger ; those of a teacher
D. more dangerous ; those of a teacher

A. dangerouser ; a teacherB. more dangerous ; a teacherC. greater danger ; those of a teacher(答案→)D. more dangerous ; those of a teacher解析：英语中由构词法派生出的形容词或副词比较级与最高级一律前面加more各the most构成。dangerous是由danger派生出的形容词，因此其比较级是more dangerous ; 在比较句中，一定要使比较的东西是一致的。为了避免重复，需比较的对象如果是单数，应该使用that of…代替，如果需比较的对象是复数，则用those of …，请看以下两个例句，并理解上述说法：The climate in Florida is as mild as in California . (佛罗里达州的气候与加州的气候一样暖和。) Classes in universities are more difficult than those in colleges . (大学本科的课程比大学专科的课程更难。)

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