How did each of the following military, economic, or political issues apply to world war i?

natural shipping:

trench warfare:

u-boats:

liberty bonds:

Natural shipping: Germany had a policy of unrestricted attacks on shipping vessels thought to be carrying troops, supplies or weapons for the Allies. This policy was suspended after vigorous protests by the USA because it violated American neutrality. In 1917 Germany reactivated this policy and the US finally decided to declare war on Germany in April of the same year.

Trench warfare: Trench warfare was devastating for both belligerents. The cold, the chemical weapons, the bombs, the fighting the diseases, the malnutrition, the unsanitary conditions killed millions of young soldiers. Due to the devastating loses, this generation of young victims and survivors came to be known as the Lost Generation.

U-Boats: Germany greatly developed this method of warfare and sank hundreds of shipping and military ships from Allied and neutral nations.

Liberty Bonds: these were debt securities that were sold to the general population to finance the war effort. Billions of dollars were collected thanks to the liberty bonds. There were cases of malfeasance by stock brokers in Wall Street.

the correct answer option is: weapons.

explanation:

tensions rose as the two opposing superpowers competed for 'weapons'.

referring to the cold war (1945-1991), the two superpowers, usa and ussr, experienced a phase of struggle and conflict with each other. these two superpowers considered each other as a threat to their survival and thus opted for policies to strengthen their positions.

the two superpowers never went to war with each other directly but competed for weapons to preserve their positions.