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
