a波正常，b波下降最常见的眼病是（）

A.视网膜色素变性

B.视网膜中央动脉阻塞

C.糖尿病视网膜病变

D.视网膜血管畸形

E.脉络膜色素细胞瘤

After having a cup of tea, he asked for _____.

A．two more

B．more two

C．more than two

D．two cups