（2011·唐山市摸底）7．The World Expo 2010 is being held at a time ． the world is looking for a new kind of balance between nature and cities
A．when B．where C．which D．that
A考查定语从句的关系词。此处time作先行词，其在定语从句中作时间状语。句意：2010世博会在一个世界正在寻找新的自然和城市的平衡的时代举行。
（2011·重庆师大附中第一次月考）27.Bears often hide themselves in places ________ can’t be found by hunters.
A. in which B. where C. that D. 不填
