Task 5:
In the dialogue, the woman is having a hard time dealing with the problem of scheduling conflict between the portrait class and her brother's retirement party which starts at the same time at 4 o'clock tomorrow. There are two solutions.
First, the man offers to cover the class for the woman, but he hasn't taught portrait class for years. The second solution is to teach the class herself so that the students could be well prepared for the next week's examination, but the woman has to miss the party.
From my perspective, I would suggest the woman to take the first advice for the following reasons. First, just like the woman said, the materials can help the man with the teaching although he has been away from portrait class for years. Moreover, it is a shame to miss the party because it is sort of a "once in a lifetime" thing, and the woman should cherish such an opportunity to get together with family members and value such a beautiful memory.