下列哪一项试验出现阳性反应对于PNH的确诊意义较大()
A.蔗糖溶血试验
B.酸溶血试验
C.酸化甘油溶解试验
D.优球蛋白溶解试验
E.抗人球蛋白试验
参考答案:B
比较下列一组数的大小.8131,2741,961
Mobile phones are very popular nowadays and they are_______ than before.
A.cheap
B.cheaper
C.cheapest
D.the cheapest