could have done有两个意思:1)本可以做而没有做 如:YOu could have turned to me for help,but you didn't.2).could 可以表示可能性 如:Don't worry--they could have just forgotten to phone.别担心,他们可能只是忘了打电话而已.
本题中倾向于第二个意思,这可能是我能想到的最好的礼物了!
could have done有两个意思:1)本可以做而没有做 如:YOu could have turned to me for help,but you didn't.2).could 可以表示可能性 如:Don't worry--they could have just forgotten to phone.别担心,他们可能只是忘了打电话而已.
本题中倾向于第二个意思,这可能是我能想到的最好的礼物了!