In the US they focus on creative thinking skills, ________ in China they only focus on theory.[ ]

A. since  

B. when

C. while  

D. now that

洋地黄类药物最适用的情况是（）

A.扩张型心肌病发生快速室率心房颤动伴肺淤血

B.肥厚梗阻型心肌病

C.二尖瓣狭窄伴肺淤血

D.心包积液伴呼吸困难

E.主动脉瓣狭窄伴肺淤血