在正常市场和运营状态下，房地产的经营效益大于其运营成本的持续时间称为()。
A、折旧年限
B、耐用年限
C、经济寿命
D、自然寿命
参考答案：C
This is my good friend. _______ name is Gina Green.
A. His B. Her C. Your
On cargo booms，preventers are（）.
A.auxiliary guys
B.extra fair leads
C.steel bands
D.stops
