锡铅合金镀层呈（）颜色。
A、浅灰色
B、银白色
C、金黄色
D、黑色
参考答案：A
与调幅波相同，调频波信号的频谱集中在（）附近。
I often mistake him for his brother, because he _____ his brother so much.
A．is similar
B．resembles
C．looks as
D．is alike
