flowers --- along the road last yeara\ plantb\ plantedc\ are plantedd\ were planted请您说明理由好吗?

flowers --- along the road last yeara\ plantb\ plantedc\ are plantedd\ were planted请您说明理由好吗?
flowers --- along the road last year
a\ plant
b\ planted
c\ are planted
d\ were planted
请您说明理由好吗?

flowers --- along the road last yeara\ plantb\ plantedc\ are plantedd\ were planted请您说明理由好吗?
d.were planted
原因如下
1.花是 “被种”,所以用被动语态
2.last year "去年",所以用过去被动时

d.一般过去时，如果木有lastyear就选c

选D，肯定不选A（单纯的实义动词），D是单纯的动词过去式（花是要被种的），C是现在的被动语态而题目说last year。

首先，由last year判断是一般过去时态，然后，主语是物（flowers）,故用被动语态，选D，意思是：去年沿着这条路种了很多花。