题目

On Thursday afternoon Mrs. Clarke, dressed for going out, took her handbag with her money and her key in it, pulled the door behind her to lock it and went to the Over 60s Club. She always went there on Thursdays. It was a nice outing for an old woman who lived alone. At six o’clock she came home, let herself in and at once smelt cigarette smoke. Cigarette smoke in her house? How? Had someone got in? She checked the back door and the windows. All were locked or fastened, as usual. There was no sign of forced entry. Over a cup of tea she wondered whether someone might have a key that fitted h耀斑现象发生在太阳的A.内核区B.光球层C.色球层D.日冕层