Jasper has put up no parking signs outside his gate,but these have not had any effect.
问题描述：
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定形式吧?
知道了，还是现在完成时态，has been ,put 的过去分词还是put!
答
两个并列的现在完成时语态句子.前后都是现在完成时.这不难看出啊,有什么问题呢?
Jasper 已经在他门口竖起很多不要停车的标志（signs复数,所以应该是很多的） ,但这些标志没有任何作用