祈使句：Be careful! Don't ... — 英语选择题
题目
Tom 想提醒妹妹：过马路时要小心，不要踢球。下列哪句话表达得最恰当？ A. Be careful! Don't play football on the road. B. Be careful! Play football on the road. C. Be careful! Don't play football in the classroom. D. Don't be careful! Play football on the road.