唐代和宋代都有谏官。唐代谏官由宰相荐举，主要评议皇帝得失；宋代谏官由皇帝选拔，主要评议宰相是非。这说明[ ]

A．唐代君主的权力不受制约

B．唐代以谏官削弱宰相的权力

C．宋代谏官向宰相和皇帝负责

D．宋代君主专制的程度高于唐代

Galvanizing would be suitable for protecting wire rope which is used for（）.

A.cargo runners

B.stays

C.topping lifts

D.All of the above