问题 选择题
一袋中有大小相同的2个白球,4个黑球,从中任意取出2个球,取到颜色不同的球的概率是(  )
A.
2
9
B.
4
9
C.
4
15
D.
8
15
答案

由题意知本题是一个古典概型,

试验发生包含的所有事件是从6个球中取2个,共有C62种结果,

满足条件的事件是取到颜色不同的球,共有C41C21种结果,

根据古典概型公式得到P=

C14
C12
C26
=
8
15

故选D.

材料题

“人固有一死,或重于泰山,或轻于鸿毛”

请回答:

(1)上述材料出自哪位历史人物?他生活在什么时代?    

                                                                                                                                                            

(2)这段话的意思是什么?    

                                                                                                                                                            

(3)他的主要贡献是什么?如何评价他? 

                                                                                                                                                            

(4)读了这段话你有何感想?

                                                                                                                                                            

单项选择题