Question

There is a system ________the waste is disposed of using the principles of ecology.

A．which

B．where

C．that

D．at which

Answer 1

B

试题分析：考查定语从句：句意：现在有个系统利用生态学原理处理废物。先行词是a system，定语从句中缺少地点状语，用where引导定语从句，D选项如果是in，也是对的，选B。