The US entered World War Two on December 8th,
1. 1939
2. 1940
3. 1941
4. 1944

1941

Explanation:

The U.S joined the war after the Japanese bombed Pearl Harbor

they required less loading and unloading

explanation:

the shipping container improved shipping because it cut down on unloading time by three weeks, eliminated wasted space, and allowed ships to carry.

the right answer for the question that is being asked and shown above is that: "their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.  " the  participant in european imperialism is being described below is that  their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.