Answer:
The Crusades were organized by western European Christians after centuries of Muslim wars of expansion. Their primary objectives were to stop the expansion of Muslim states, to reclaim for Christianity the Holy Land in the Middle East, and to recapture territories that had formerly been Christian.
Explanation:
Boomed in 1920 because economy
Organic catalyst is the answer
U Boat is called Undersea Boat. The following is the reason why germans used them to attack.
<u>Explanation:</u>
- U Boat is the abbreviation of Undersea Boat.
- It is also called as Unterseeboot.
- It is called a German submarine.
- There are many ships during the war.
- So to sink those many ships germans used the Undersea boat.
- The Germans sank 5000 ships during the world war.
- They measured more than 13 million gross register tons during the war.
- The Germans used them to attack those ships using the Undersea boat.