______确定圆的大小，______确定圆的位置．
由圆规画圆的方法可以得知，半径决定圆的大小，圆心可以确定圆的位置；
故答案为：半径，圆心．
It is ______ for him to finish the heavy work in such a short time. He is not a god (上帝). [ ]
A. possible
B. impossible
C. unnecessary
D. likely
