[speaker001:] I hear scientists in the US have discovered a new AIDS vaccine.
[speaker002:] Does it work?
[speaker001:] I don 't know. The report says it is better than the old vaccines.
[speaker002:] Don 't count on it. I think the best way to prevent AIDS is to keep yourself clean by having clean sex and keeping a regular sex partner.
[speaker001:] Right. That 's why doctor say AIDS prevention means cleanness.