男性患者，72岁，查体见角膜边缘及周围出现灰白色浑浊环，是由于下列何种原因所致
A. 类脂质沉着
B. 铜代谢障碍
C. 铁代谢障碍
D. 维生素C缺乏
E. 白内障
关于心音的叙述，正确的是
A. 第一心音标志着心室舒张开始
B. 第二心音标志着心室收缩开始
C. 第三心音出现在心室舒张早期
D. 第四心音出现在心室收缩早期
E. 心音有4个，通常能听到S1、S2和S4
The reason he has been such a success ______ he never gives up.
A. is what
B. is that
C. is because
D. is
"I like your furniture very much.""Thank you. We bought ______ in Denmark."
A. the most of them
B. most of them
C. the more of it
D. most of it
微信支付 
支付宝支付