a clerk and secretary/a clerk and a secretary

【问】 (1) A clerk and secretary are needed. (TOEFL)

(2) A clerk and a secretary is enough for such a small office as ours. (TOEFL)

为什么在句(1)中secretary之前不加不定冠词是错误的，而在句(2)中加上不定冠词又是错误的呢?

【答】 当and所连接的两个名词或名词短语表示一个人的两种身份，而实际上指的是一个人时，照例，只在第一个名词之前使用不定冠词，第二个名词之前不加不定冠词。句(2)便属于这种情形，从谓语动词使用单数(is)，就可以看出这一点。a clerk and secretary指的是一个办事员兼秘书。

当and所连接的两个名词或名词短语表示两个人时，则在第一个名词之前和第二个名词之前都必须加不定冠词。句(1)便属于这种情形。句(1)中的谓语动词使用复数，可以充分说明这一点。因此，应将句(1)中的a clerk and secretary改为a clerk and a secretary。

请做下面的英语试题：

1. “What is he?”“He is____.”

A. a poet and novelist B. a poet and a novelist

C. poet and novelist D. the poet and novelist.(TOEFL，70. 2)

2. He is a brave and an intelligent soldier.(VST)

(参见and ¹⁷)