基于MPLS标签最多可以标示出几类服务等级不同的数据流？（）。
A.2
B.8
C.64
D.256
参考答案：B
These two houses are similar _____ they both have a large garden with many kinds of flowers.
A．to that
B．in which
C．in that
D．to which
* * 毛滴虫病原学检查常用的方法是：
A．生理盐水涂片法B．动物接种法C．骨髓穿刺检查D．碘液涂片法E．薄厚血膜涂片法
