Misc: What do you call substances that will not let thermal heat pass through them?

Questions

Category: Canadian Music : This inspirational song by Gene MacLelland was a hit for Anne Murray in 1970.?

In 1900 Spanish----------- War ends.?

In 1977 Soyuz ---------- is launched.?

In 1838 A London pedestrian walks 20 miles backward and 20 miles forward in ---------- hours.?

In 1977 Soyuz ---------- returns to Earth.?