听力原文： Indonesian and Aceh rebels on Monday signed a peace treaty to end nearly 30 years of fighting that killed 15,000 people, but rebel leaders voiced concern about government troops remaining in the region. The signing ceremony in Helsinki followed seven months of talks mediated by former Finnish President Martti Ahtisaari, who spurred the two sides to agreement to help international aid reach Aceh province, which was devastated by last year's tsunami. Hostilities in the area broke out in 1976. Although many Acehnese wanted an end to the bloodshed, there was general support for independence because of abuses. What did Indonesia and Aceh rebels do on Monday?