已知1<x<3,化简|x-3|+|x-1|等于( )
A.2x
B.-2
C.2
D.-2x
∵1<x<3,
∴x-3<0,x-1>0,
则原式=3-x+x-1=2.
故选C.
In 1831, Faraday discovered that electricity moves through a wire ________ a magnet(磁铁) is moved near the wire.
A.where
B.so
C.when
D.but
天然气计量温度可以直插或斜插,斜插时与管道轴线呈()
A、30o
B、45o
C、60o
D、90o