The German U-boats blocked British Isle and attacked merchant ships affecting the trading business of US with British, but at some stage the U-boats started to attack ships taking the lives of unarmed passengers, as with the Lusitania ship, which 120 American died. The Germans were asked to stop the attacks but they did not and many US ships sank, shedding off US citizens lives. The submarine warfare enraged the US neutrality which then turned against the German and declared war on March 1 in 1917.
Mehmed ll is your answer, hope this helps!
Yes, you are correct about change of water into water vapours , also you will think it is doesn't have any importance and is waste for the plant energy. But it is a “NECESSARY EVIL” as it cools down the plant , transport water,minerals and also Plant hormones,etc. May you got your answer
