Jasper has put up 'No Parking' signs outside his gate这里的signs为什么要用复数?

jasper has put up no parkingsigns outside.jasper第三人称 为什么 put不加S? Jasper has put up No Parking signs outside his gate分析下句子结构 these have not had any effect这里为什么用these呢?能不能用this.these指的是Jasper has put up“no pthese指的是Jasper has put up“no parking”signsoutside his gate 这件事 Jasper has put up 'No Parking' signs outside his gate这里的signs为什么要用复数? 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. Jasper has put up no parking signs outside his gate,but these have not had any effect.Jasper has put up no parking signs outside his gate,but these have not had any effect.逗号前这句是什么时态?后面的这句应该是现在完成式的否 Another Supermarket has been put up near our house是什么意思?里面的put up是什么意思呀？ the sports meeting has put up because of rain Attention,please.The flight has to be_____.A.put on B.put off C.put away D.put up Put up put up put up put up ,put out The plan of cleaning up the city parks has been (put on ,put up,put off,put down)till next Sarurday put off,put up,put down,put put out,put away,put up,put our sports meeting has been ( )because of the bad weather.a.put on b.put up c.put off d.put out put away.put up.put off.put up