Metaphor: King compares injustice and oppression to sweltering heat and freedom and justice to an oasis. Analysis: King repeats the sweltering heat metaphor toward the end of the speech, referring specifically to Mississippi, a state where some of the worst offenses against blacks had been carried out.
He uses a technique called enjambment. It is when you don't end your thought within a single line, but transfer it to the next line of the poem, which is evident here.
Yes, it is a good idea. It's even better if you know the most commonly used language of whatever place you are traveling to. Like if you were to travel to France it's a good idea to be fluent in French.
