神经对感应电刺激无反应或兴奋阈增高但对直流电刺激有反应,不论其阈值高低为()。
A.绝对变性反应
B.部分变性反应
C.无明显变化
D.无变性反应
E.完全变性反应
参考答案:B
句型转换。(10分)
小题1:Peter has studied Chinese for five years.(对划线部分提问)
小题2:He teaches English in our school.(变成被动语态)
小题3:It is a very interesting film.(改为感叹句)
小题4:She had some rice and chicken for supper in the evening.(改为否定句)
_________________________ __________________
小题5:When does the plane leave? I want to know.( 合并为宾语从句)
设二元函数f(u,v)具有二阶连续偏导数,且满足
,又g(x,y)=f(x2-y2,2xy),则
=______.