<span>select one:
a. acoustic countermeasures.
b. sonar.
c. centimetric radar.
d. both sonar and centimetric radar.
e. all these answers are correct.
A quick google search said centimetric radar was invented in 1935 during the range of WWII.
Hope I helped some</span>
Answer:
The most convincing 'internal' factor behind southern defeat was the very institution that prompted secession: slavery. Enslaved people fled to join the Union army, depriving the South of labor and strengthening the North by more than 100,000 soldiers. Even so, slavery was not in itself the cause of defeat.
Explanation:
Productive Recources. hope this is right
