A rectangle is defined to be "silver" if a
题型：单项选择题
问题：
A rectangle is defined to be "silver" if and only if the ratio of its length to its width is2 to 1. If rectangle S is silver, is rectangle R silver ？（）
(1)R has the same area as S.
(2)The ratio of one side of R to one side of S is 2 to 1.
A．条件(1)充分，但条件(2)不充分．
B．条件(2)充分，但条件(1)不充分．
C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D．条件(1)充分，条件(2)也充分．
E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．