In a study published in 2011 , researchers asked participants to keep their eyes focused on one of the following objects on a changing chessboard : a series of moving discs in study one ; or a stream of letter and digits in study two .
If you remove two diagonally opposite corners , it will be impossible to cover the chessboard .
如果你移开连成斜线的相对的2个方格,那么无法盖住棋盘。
However , when you started , the cards on the diagonal were the wrong way up compared to the chessboard pattern .
不过,在开始时,对角线上的纸牌是棋盘格的相反朝向。
A chessboard king eluding checkmate , colonel qaddafi has begun retracing the finale of saddam hussein , the first of the arab world 's tyrants to fall to regime change .
Messrs brynjolfsson and mcafee fear that the technological advances of the second half of the chessboard could be disturbingly rapid , leaving a scourge of technological unemployment in their wake .