【问】 a type of与a type of a哪个格式是正确的?另外，a type of machines的说法是否正确?
 【答】 以下三种用法都是可以接受的：
 A. a type of(+可数名词或不可数名词)
 1. He invented a new type of stethoscope.
 他发明了一种新型听诊器。
 2. He was evidently not accustomed to that kind of thing.
 很明显他不习惯于此类事情。
 3. This sort of thing can't go on.
 这类事不能再继续下去了。
 4. I would prefer a new type of education for my children. (Chambers)
 我愿意让我的孩子们受一种新型的教育。
 5. The eighteenth century developed a completely new kind of novel.
 十八世纪时出现了一种完全新型的小说。
 6. “I haven't any ideas for Ann's present. ” “Do you know____she prefers?”
 A. what is type of jewelry that
 B. the types jewelry
 C. what jewelry type
 D.the type of jewelry(TOEFL，75. 5)
 B. a type of a
 1. a new kind of a machine
 一种新型的机器
 2. He wanted a job，any sort of a job. (VOA)
 他想找工作，任何类型的工作都可以。
 3. I didn't think you were that kind of a person. (Lewis)
 我没有料到你是这种人。
 但是，有的语言学家说，在正式英语中应去掉不定冠词a(an)：
 1. This kind of greeting card is sold only at stationery stores. (Perrin)
 这种祝贺卡只在文具店里出售。
 2. Only a bigot would be interested in that sort of book.(同上)
 只有抱有偏见的人才对那种书感兴趣。
 3. It was a kind of animal with long ears and a short tail. (ELD)
 那是一种长耳朵、短尾巴的动物。
 C. a type +复数名词，如a new kind of machines：
 1. What sort of circumstances is this Mrs. Jones in?
 这位琼斯太太处在什么情况之下?
 2. What sort of novels do you like?
 1233 types of
 你喜欢哪类小说?
 3. What sort of flowers are these?
 这些是什么花?
 4. These are a peculiarly sharp kind of swords.
 是一种特别锋利的剑。
 5. new kinds of computors(CGEL)
 新型计算机
 考生应当注意，许多标准考试的测试专家目前只承认A种用法的正确性。请注意下面的试题：
 1. Dr. Lorber insists that language cannot be turned at will into a sort of an algebraunder the rule of strictness and fixity. (1984年日本模拟题)
 2. The automobile industry is manufacturing a new type of a motor that will consumeless gasoline and cause much less pollution.(攻读硕士学位研究生入学考试英语试题，81A)
 3. After reviewing the troops，the visiting general commented that he had finally seenthe kind of a soldier that the nation needs. (TOEFL，74.1)
 [参见 what kind of(a)]