What are the four land forms created by streams.

Earth's surface that is part of the terrain. Mountains, hills, plateaus, and plains are the four major types of landforms

Explanation:

A landform is a feature on the Earth's surface that is part of the terrain. Mountains, hills, plateaus, and plains are the four major types of landforms.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.