求教两道很傻的语法题FROM SAT OG TEST8

问题描述:

求教两道很傻的语法题FROM SAT OG TEST8
In a world that the rate of technological and social change accelerates frighteningly,change itself often seems to be the only constant.为什么是in a world that 这个位置有错?
第二个就是很傻的了:introducing new ideas and replacing old ones is ...这是两个动作,为什么用is?

in a world where...因为in a world是地点状语所以后面应该是地点状语从句
应该是把这两个动作作为一个完整的整体来看采用的is,因为这两个动作时一个代替另一个的关系,在时间上是承接的连续的,当然如果用are也没问题