1.Four evergreen shrubs stood at each corner,where they stru

1.Four evergreen shrubs stood at each corner,where they struggled to survive the dust and fumes from a busy main road.
后半句意思是他们经受着从繁忙的大街上传来的尘烟,挣扎的生存着.我认为they struggled to survive,与后面的the dust and fumes from a busy main road中间少了一些连接,但不知道少了什么词.请分析一下where这句语法.
2.On the mantelpiece there was a salt cellar and pepper-pot.
这里的was是不是应该为were?后面不是复数吗?