根据题目要求完成下列任务，用中文作答。
下面是某初中课堂教学片段。
T: (referring to a picture) Where is John, Li Lei?
S1: He has gone to Shanghai.
T: How many times has he been to Shanghai?
S1: He has been to Shanghai for only once.
T: (referring to another picture) Where is Mary, Wang Wei?
S2: She has gone to the library.
T: How many times has she been to the library a week?
S2: She has been to the library twice a week.
