路灯控制不当或建筑工地的聚光灯，照进住宅，影响居民休息，是一种( )。
A．视觉污染 B．灯光污染C．不可见光污染 D．电磁波辐射污染
参考答案：B
设x2-xy+y2=1（x，y∈R），则x2+y2的取值范围为（ ）。
Excuse me, Marcia, a reporter from Vanity Fair _____ all day. Could you speak to her now? [ ]
A. phones
B. has phoned
C. has been phoning
D. phoned
