Thedestructionofthetwintowers_________shockandangerthroughouttheworld．
Hiswifehasbeen_______alotofpressureonhimtochangehisjob.
设函数f(x)=ln(3x)，则 f'(2)=（）
Despitehavingreceivedpositivereviewsbyindustrycritics,salesofthedigitalMP3playerhavebeenquite_______(disappoint).
Itisestimatedthat，currently,about50，000speciesbecome_____everyyear．
