根据内容回答下列各题，For some minutes, all was quiet in the street．Then from across the street someone came walking．It looked like a man of middle height, dressed in a big raincoat, a soft hat and rubber-soled boots or shoes, and little sound while walking．No one was in sight．It was a street with two rows of about fifty small houses and there were three lamps on either side．The lamp nearest to the child’s house could be seen clearly, but the others were almost hidden by the smoky air．A car passed the end of the street and its lights showed faintly, but clearly enough to show the smooth skin of a woman’s face．The car disappeared as the woman, wrapped up in her coat, reached the doorway of the child’s house．She put a key in the lock quickly, pushed the door open and stepped inside, then closed the door without looking round．She began to breathe hard．She leaned against the door for a moment, then straightened up as if with an effort, and walked towards the door of the front room, the passage leading to the kitchen, and the narrow staircase．She hesitated outside the door, then went up the stairs quickly but with hardly a soun D．There was enough light from the narrow hall to show the four doors leading off a small landing (楼梯平台)．She pushed each door open in turn and shone a torch inside, and the light fell upon beds, walls, furniture, a bathroom hand-basin, a mirror which flashed brightness back; but this was not what the woman was looking for．She turned away and went downstairs, and hesitated again at the foot of the stairs, then turned towards the kitchen．Clearly there was nothing there, or in the small washroom that she wante D．Two rooms remained; the front room and a smaller one next to it．She opened the front room door．After a moment, she saw the child’s bed and the child．The lights of the car passing the end of the street showed that .