问题补充：
The teacher suggested the dictionary at once.
A. be referred to be bought
B. be referred to being bought
C. referred to be bought
D. referred to being bought
答案：
A. be referred to be bought
B. be referred to being bought
(答案→)C. referred to be bought
D. referred to being bought
解析：这题考查过去分词做定语和虚拟语气的用法：referred to是过去分词做定语，修饰the dictionary，又因为suggest表示“建议”时，宾语从句用sb （should） do的虚拟语气，选C。
