下列物质中，通常情况下属于导体的是（   ）

    Mrs Smith's living room is large. There is a television in the room. The television is near the window. There are some magazines on the television. There is a table in the room. There are some newspapers on the table. There are some armchairs in the room. The armchairs are near the table. There is a stereo in the room. The stereo is near the door. Mrs Smith often listens to music from it.

$\frac{3}{5}$ ＋ $\frac{3}{7}$ ＋ $\frac{2}{5}$ = ( )

下列各句中，没有语病的一句是（    ）