2道语法题1.Extendingalongseveralcityblocks"are"arowofginkgotrees...文中的are是错误的.为什么不是are?我们不是会说AgroupofstudentsAREcrossingtheroad?2.Africa'sKanemempire,afterenduringforoverathousandyears,

Question

2道语法题
1.Extending along several city blocks "are" a row of ginkgo trees...
文中的are是错误的.为什么不是are?我们不是会说A group of students ARE crossing the road?
2.Africa's Kanem empire,after enduring for over a thousand years,is believed to have fallen into decline when trade centres "shift" outside its boundaries.
文中shift是错误的.请问正确的用法是什么?为什么?
虽然我赞同这份嗳_赞的第二个解释，但是我也经常看到“物”自己shift...比如The wind shifted from the south to the west.“Wind”本身就是“物”吧？

Answer 1

1.“Extending along several city blocks ” 为一个整体,强调“沿着街边的” 为单数,不能单单看到blocks就为复数.
A group of students 中强调的是 students 因此为复数.
2.trade centres 是“物”,不能自己转化,应为被动 are shifted