电镀铜镀液中的主盐是（）。

A.氟硼酸铅

B.硫酸镍

C.硫酸铜

D.氟硼酸锡

________ that saw the rise of quite a number of new writers.

A．During the first half of the 18th century

B．That it was in the first half of the 18th century

C．It was in the first half of the 18th century

D．It was the first half of the 18th century