把x=2y=-1代入方程3x+ay=1,
得6-a=1,
解得a=5.
-- ? -- It’s terrible.
A.What’s he doing
B.How is he?
C.How’s it going
D.What’s the weather
治痰热蒙蔽心窍之癫痫发狂及痰厥等证
A.黄柏配苍术B.橘皮配半夏C.郁金配白矾D.磁石配朱砂E.白及配乌贼骨