治疗疫毒痢内闭外脱的首选方剂是：
A．独参汤
B．附桂八味丸
C．参附汤
D．四逆汤
E．参附龙牡救逆汤
参考答案：C
We did a research to find how the family backgrounds influence the children's _____ towards English learning. [ ]
A. points
B. ideas
C. attitudes
D. sights
分解下列因式：
（1）a4-a2
（2）1-4x2+4xy-y2．
