Mary had to go to a meeting，so she left her children at home.
A. playing
B. played
C. to play
D. having played
网友回答
(答案→)A. playing
B. played
C. to play
D. having played
解析：考察动词leave用法。本句的动词leave使…处于…状态；leave sb doing sth让某人做某事；本句中的her children与play构成主动关系，且表示正在进行，故使用doing的形式。句意：Mary不得不去开会，所以她让她的孩子在家里玩。故A正确。