设随机变量，且，则参数与分别是（　）．

<span style、"font-size: 10.5pt; font-family: 'Times New Roman', serif;" lang="EN-US">0, 2 </span>

<span style、"font-size: 10.5pt; font-family: 'Times New Roman', serif;" lang="EN-US">0, 4 </span>

<span style、"font-size: 10.5pt; font-family: 'Times New Roman', serif;" lang="EN-US">2, 0</span>

<span style、"font-size: 10.5pt; font-family: 'Times New Roman', serif;"> 4, 0 </span>