In the hot sun the surface of the road seems wet, but that is on

In the hot sun the surface of the road seems wet, but that is only an ______.
A、allusion
B、illusion
C、expectation
D、exception
【正确答案】：B
【题目解析】：该题考查名词辨析。allusion意为“影射，暗指”；illusion意为“错觉，幻想”；expectation意为“期待，预期”；exception意为“例外”。本句的句意为“在太阳的照射下路面看上去是湿的，但这只是个错觉。”