Why is siberia much colder than western russia?
ocean winds pound most of siberia.
ocean winds cannot reach siberia.
mountains cover all of siberia.
western russia is much closer to the equator.

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.