选择:write a passage about ( ) in English./ write ( ) passage in English.

问题描述:

选择:write a passage about ( ) in English./ write ( ) passage in English.
A,600 wrods; a 600-words
B.600-wrod;a 600-wrods
C,600 wrods;a 600-words
为什么?

600 words;a 600-word;
第一个不用解释吧,第二个做定语,比如100米赛跑,100-meter race,用“-”连接时为单数,可以认为是固定用法.