视杯外层形成视网膜的（）
A.色素上皮层
B.视杆细胞层
C.视锥细胞层
D.外核层
E.神经节细胞层
参考答案：A
请写出下列离子方程式：
（1）铁片插入硫酸铜溶液中______
（2）氢氧化钠溶液与稀盐酸混合______．
—I haven't seen Zhang Tong for four days? Is she ill?
— __ . Her mother told me that she was in hospital. [ ]
A. I hope not
B. I'm afraid so
C. I don't expect
