A:take choices; base o
B:make choices; based o
C:do choices; basing o
D:have choices; to base o
澳大利亚海岸南北延伸2 000多千米的珊瑚礁——大堡礁位于( )
若x-y≤0x+y≤1x≥0,则z=x+2y的最小值为( )
Weather________,the picnic will be held as scheduled.