何为正线?
参考答案:
正线是指连接车站并贯穿或直股伸入车站的线路。
已知x,y∈R,且2010x+2011y>2010-y+2011-x,那么( )
A.x+y<0
B.x+y>0
C.xy<0
D.xy>0
Washington, a state in the United States, was named _____ one of the greatest American presidents.
A.in control of
B.in honor of
C.in favor of
D.by means of