球状石墨生成的两个必要条件（） A.较大的过冷度 B.较大的铁液与石墨间的界面张力

纠错编码按监督码与信息码之间的关系分（）和（）。

Not only _______ interested in football but _______ beginning to show an interest in it. [ ]

A. the teacher himself is, all his students are

B. the teacher himself is, are all his students

C. is the teacher himself, are all his students

D. is the teacher himself, all his students are

在出口信用保险中，保险单对被保险人向某特定买方出口货物所承担的最高赔偿限额称为保证金额。

仅在新生儿期出现的脑电图图形是（）。

A.交替型图形

B.催眠性θ节律

C.α节律解体

D.顶尖波

E.睡眠纺锤波

在最坏情况下，堆排序需要比较的次数为 【2】 。