【单选题】People in ancient Greece understood that______.
A.
some tree bark and leaves could be used as aspirin
B.
some tree bark and leaves had certain medical effects
C.
aspirin was a good pain killer
D.
aspirin could cure arthritis
【单选题】执行M O V I E,#81H指令的意义是
【简答题】设AS曲线方程为y s =500,AD曲线方程为y D =600-50P。 (1) 求供求均衡点。 (2) 如果AD上升 10% ,求新的供求均衡点。
【单选题】执行M O V I E,#81H指令的意义是:( )
【单选题】关于电导率仪的使用,下面哪一点叙述不正确
A.
把“温度”钮置于25℃刻度线时,测定值是溶液在测量温度下的电导率值
B.
需要调节“常数校正”,使仪器显示出电导池系数的数值