The article _a_ or _an_ agrees with nouns in the _singular_ number only,
individually or collectively; as, "_A_ star, _an_ eagle, _a_ score, _a_
thousand."
RULE I.
English Grammar in Familiar Lectures Accompanied by a compendium, embracing a new systematic order of parsing, a new system of punctuation, exercises in false syntax, and a system of philosophical grammar, in notes, to which are added an appendix and a key to the exercises : designed for the use of schools and private learners · 第 252 / 369 题