The student has waited at the entrance for more than half an hour.(划线部分提问,划for more than下
问题描述：
The student has waited at the entrance for more than half an hour.(划线部分提问,划for more than下
答
The student has waited at the entrance for more than half an hour.(划线部分提问,划for more than half an hour
How long have the students waited at the entrance?