Read the following text. Then, answer the questions.

Christine and Margaret are friends. They are both busy because of their work and their study. Finally, they can meet for coffee on Wednesday.

"What are you going to do this weekend?" asks Margaret.

"Well, I have a big project to finish for my design class. But if I can finish it by Friday, I'll do something fun as a treat," says Christine.

"That sounds great!" replies Margaret. "I think the ballet is coming to town. If it isn't too expensive, I'm going to buy tickets. Would you like to come?"

"Well, I don't really like ballet very much. If you want to go to the ballet in the evening, let's do something in the morning," says Christine.

"All right. If you have the energy, let's go swimming!" suggests Margaret.

"That sounds great! If I don't call you on Friday, send me an email at work," agrees Christine. "And if I don't answer, call me again. And if I don't pick up… oh, let's just make plans now! I'm too busy to plan later!"

What do they plan to do at weekend?