有读者问一道选择题：
(1)The story sounds _____.
A. to be true B. as true
C. being true D. true
答案是D，为何不选A?
连系动词sound, smell, taste等皆不后接“to be +形容词”，而只后接形容词，再如：
(2)It smells sweet.
(3)It tastes nice.
只有少数连系动词，如seem, appear, prove等，为了强调其语气，始可后接“to be+形容词”，如：
(4)It seems to be right.
(5)He appears to be rich.
(6)It proves to be true.
