________with his parents that he is able to tell who they are from their steps.     [ ]

A.  So familiar her is                            

B.  So familiar is he    

C. So he is familiar                              

D. So is he familiar

高集物料提升机除了应当设置低架物料机应当设置的安全保护装置外，还应当设置（）。

A.断然保护装置

B.缓冲器

C.载重量限制装置

D.上极限限位器

E.下极限限位器