下列物态变化中.属于液化现象的是[ ]
A.春天,冰封的河面解冻
B.夏天,剥开的冰棒冒“白气”
C.秋天,清晨的雾在太阳出来后散去
D.冬天,屋顶的瓦上结了一层霜
B
I like working with anybody whose _____ I enjoy, because I can have a light heart with them around. [ ]
A. relation
B. standard
C. presentation
D. company
需求完全无弹性,需求曲线在数学上是一条()
A.与横轴平行的线
B.向右下方倾斜的直线
C.与纵轴平行的线
D.向右下方倾斜的直线