读“我国三大经济圈位置示意图”，完成题。
在输入语句中，若同时输入多个变量，则变量之间的分隔符号是（ ）
His parents don't allow him ________ computer games. They think they are bad for his studies.
一本科技书，小明看过80页，还剩下31页没有看，看过的和没有看过的各占这本书总页数的几分之几？
