单选题 Don't forget ______the door when you leave the classroom.
[A] to close [B] closing [C] close

【正确答案】 A

【答案解析】[解析] 本题考查动词的用法。忘记已经做过的事情：forget doing sth.；忘记将要做的事情：forget to do sth.根据句意，答案为A。
[知识拓展]remember的用法与forget相同。记得已经做过的事情：remember doing sth.；记住将要做的事情：remember to do sth.