期货市场同价格波动是不相容的,期货市场要尽可能地消除价格的频繁波动。( )
参考答案:错
解析: 期货市场需要价格的频繁波动,期货市场同价格波动是相容和相互依存的。
—Waiter, what about my food?I________for over 30 minutes.
—Oh, sorry, sir.Just one more minute, please.[ ]
A. have waited
B. was waiting
C. have been waiting
D. had waited
下面对对象概念描述错误的是 ( )
A.任何对象都必须有继承性
B.对象是属性和方法的封装体
C.对象间的通讯靠消息传递
D.操作是对象的动态属性