How do I answer 6-mark questions? Eg. "Explain why Tsar Nicholas II had become unpopular by early 1917."

The best way to answer these types of questions is to make several points, and give each one a short explanation. That way you're getting marks for the knowledge AND the analysis.I would suggest that you make 3 points. Let's think of them first:1) A movement against the Tsarist autocracy had been building since 1905, and revolutionary groups were becoming stronger.2) The Tsar was Commander in Chief of the army, but there were many defeats at the front while he was in charge.3) In the winter of 1916–17 there was starvation due to food shortages, and so strikes and demonstrations broke out.Now think of WHY each point made the Tsar unpopular, to make a full answer:Firstly, a movement against the Tsarist autocracy had been building since 1905, and revolutionary groups were becoming stronger. The Tsar was therefore losing popularity over time because he represented an outdated and inefficient system of government which many students and progressive politicians wanted to replace.Secondly, the Tsar was Commander in Chief of the army, and there were many defeats at the front while he was in charge. This made him lose the trust of the military and of the nation since he was seen as directly responsible for deaths of Russians in battle, and national humiliation at the hand of the Germans.Finally, in the winter of 1916–17 there was starvation due to food shortages, and so strikes and demonstrations broke out. People resented the Tsar for not solving their hardships and not leading the country efficiently, and so by 1917 the autocracy was the most unpopular it had ever been.This answer would give you full marks. In fact, even if you just explained two of the points, you could get all 6 marks, but writing three means that you've got a backup in case one of the points goes a bit wrong.