【题目】But for the survival instinct that nearly all creatures have, more species from the earth.
A. could disappear B. might have disappeared
C. should disappear D. will have disappeared
在线课程【答案】B
【解析】考查虚拟语气。句意：如果不是所有物种都具备的生存本能，更多的物种可能已经从地球消失了。根据句意可知，此句使用了虚拟语气的结，根据句意可知虚拟过去，故选B。