The following steps describe how sedimentary rock forms at the bottom of a river. Which two steps involve erosion?

1. A large rock breaks down into sediment.

2. The water transports and deposits the sediments.

3. The water also transports calcite and clay, which glue the sediments together.

4. The upper layers of deposits put pressure on the lower layers.

5. Rock forms as the layers of sediment and glue compact and cement together.