∵[x]=5，[y]=-3，[z]=-2，∴[-y]=2，∴[x-y]+[z]≤[x-y+z]≤[x-y]+[z]+1，[x]+[-y]≤[x-y]≤[x]+[-y]+1，∴[x]+[-y]+[z]≤[x-y+z]≤[x]+[-y]+[z]+2，∴5+2-2≤[x-y+z]≤5+2-2+2，∴5≤[x-y+z]≤7，故[x-y+z]可以的取值有5，6，7，共3个．故选C．
