Inthepastfewyears,somanyareasthroughouttheworldhavebeenhitbysuchdestructiveearthquakes,snowstormsandtsunamis________wehaveneverexperiencedbefore,________makesusworriedalotaboutnaturedisasters.
A.that; thatB.as; whichC.which; itD.when; as在线课程B
考查定语从句。定从________ we have never experienced before的先行词是such destructive earthquakes, snowstorms and tsunamis，和such连用，要用关系代词as; 定从________ makes us worried a lot about nature disasters.的先行词是前面整个句子，用which引导。所以选B。