21. difference
22.difficulties
23.exciting
24.friends
25.fascinating
26.fluently
27.meeting
28.information
29.Last week, she went to the dentist
30.She had an appointment with Doctor Lai at 3o'clock
31.She saw two cavities in her teeth when she checked Lan's teeth
32.Then, She filled the cavities in Lan's teeth
33.Lan felt very pleased because her teeth stopped hurting
34.Dr. Lai told Lan not to forget to brush her teeth regularly because brushing our teeth was very important