Misc: Out of what did the ancient celts make the jack-o-lantern?

Questions

What is an extra lane on an uphill stretch of motorway provided for slow-moving vehicles called?

During World War II, which London theatre boasted, "We never closed"?

Who was British Prime Minister at the outbreak of WWI?

Who was the oldest man ever to play Test cricket when he represented England against West Indies in 1930 aged 52?

Who wrote the classic war novel "All Quiet on the Western Front"?