North Africa Desert 1950s

The transcript describes the harsh and inhospitable conditions of the Sahara Desert, where the environment is too extreme for most life forms to survive. Despite these challenges, modern advancements have allowed humans to build railways along the desert's edge, although the trains remain small due to the difficult conditions.

Explain why nothing green can grow in the described environment.

What is the significance of the small trains built along the edge of the Sahara?