圆的半径扩大2倍，面积[ ]
A．扩大2倍
B．扩大4倍
C．不变
答案：B
The salesman's ______ annoyed the old lady, but finally she gave in.
A．endurance
B．assistance
C．persistence
D．resistance
对于有规划限制条件但尚未明确的房地产，也可以适用假设开发法。 ( )
