You can’t be ______ when you camp _____ a high altitude, ________ the air is thinA.enough careful; at; whichB.too careful; at; whereC.careful enough; on;at whichD.too careful; on; that
网友回答
B解析第一空考查短语：can’t… too 再什么也不为过，第二空考查短语：at a high altitude以很高的海拔，第三空考查定语从句，先行词为a high altitude，从句中缺少地点状语。所以选B。