按要求改写句子。     

1．你难道还不相信我吗？

改为陈述句：                                                                                                      

2．警卫员立刻把黄先生的话转告 * * 。 

改为“被”字句：                                                                                                

3．毛 * * 亲手把字帖包好。 

改为反问句：                                                                                                        

4．王羲之的真迹真是世间罕有呀！ 

改为双重否定句：                                                                                                 

有两个自由度的关节是（）

A.滑车关节

B.车轴关节

C.椭圆关节

D.球窝关节

E.杵臼关节