Jasper has put up no parking signs outside his gate,but these hav_英语解答

Jasper has put up no parking signs outside his gate,but these have not had any effect.
为什么前后两句都用完成时.

人气：144 ℃　时间：2020-05-13 02:21:41

解答

“Jasper已经贴了禁止停车的标示”,用现在完成时,表示已经贴了,动作已经完成.
“但还是没用任何成效”,已经贴了,但是没成效,强调对现在造成的结果和影响.所以还是用了现在完成时.