【判断题】函数 的f(x)极大值不一定比极小值大 。
【单选题】在数据库设计中用ER图来描述信息结构,但不涉及信息在计算机中的表示,它是数据库设计的( )阶段。
【单选题】在数据库设计中,用 ER 图来描述信息结构,但不涉及信息在计算机中的表示,它属于数据库设计的 () 阶段 。
【单选题】Some birds can make several different sounds, each with meaning ______.
【单选题】听力原文:M: Since you have visited so many countries, you must be able to speak several different languages. W: I wish I could. But French and German are the only foreign languages I have ever learned to ...
A.
She hasn't learned French.
B.
She can speak several foreign languages including French.
C.
She can speak both German and French.
D.
She speaks neither French nor German.