人教选修八:Unit+5+Meeting+your+ancestors+listening,speaking+and+reading(共47张PPT)
人教选修八:Unit+5+Meeting+your+ancestors+listening,speaking+and+reading(共47张PPT)第3页

Answer key for Exercise 2

Each layer looks different as they are uncovered, so you can tell where one layer starts and another finishes. In the wastepaper basket, the most recent layer is _________, an older layer is below that and the oldest layer is ____________.

at the top

at the bottom