3 4.2 grade 4

Both canyons and valleys often have river in their bottom.

• True

• False

Deltas are formed as a result of silt deposition.

• True

• False

The Nile River Delta was formed by weathering and erosion processes only.

• True

• False

Plant roots help in trapping sediments that causes the increase of deposition.

• True

• False

They are lowland areas in between mountains and have gently sloped sides.

A land area that is formed by deposition process when a river enters a lake or a sea.

Deltas are formed when the speed of river water

• increases.

• decreases.

• doesn't change.

The delta is formed when the river stream entering all of the following, except

• a lake.

• a sea.

• a mountain.

When the speed of the water stream that is run over a mountain increases, the rate of erosion will

• increase.

• be constant.

• decrease.

Walls of canyons are characterized by all the following, except that they

• are gently sloped.

• consist of many rock layers.

• are very high.

• have great depth.