问题补充:
There is useful book and interesting magazine on the desk. They aremy brother’s.
A. a, an, all
B. a, a, both
C. a, an, both
D. an, a ,all
答案:
A. a, an, all
B. a, a, both
(答案→)C. a, an, both
D. an, a ,all
解析:
useful中的首字母u发的是/ju/非元音,故用a;而interesting中首字母i发的是/?/为元音,故用an;这里只有两本书,故用both,而all用于三者及以上,故选C。