plastic bags ,which were and are still being widely used in china .which后面为什么要用were 、

问题描述:

plastic bags ,which were and are still being widely used in china .which后面为什么要用were 、

句子的意思是“在中国,塑料袋过去和现在仍然被广泛使用”.
你就能明白了为什么用“were”.