用这些表示命令的句子来完成以下句子 Washing your hands. Be quiet. Mind the gap. Keep off the grass. 1.Little Jemmy's hands were dirty. His mum said to him, " " 2.A sigh near grassland says " " 3.The teacher said to the noisy students, " " 4.A sigh saying " " in the subway station reminds us to pay attention to the gap between the train and the platform.