题目内容：

The third week of SEAL training means Hell Week. It is on Wednesday of Hell Week that you paddle down to the mud flats（泥滩） and spend the next 15 hours trying to survive the freezing-cold mud, the howling wind and the increasing pressure from the instructors to quit. As the sun began to set that Wednesday evening, my training class, having broken the rules, was ordered into the mud. The mud consumed each man till there was nothing visible but our heads. The instructors told us we could leave the mud if only five men would quit—just five men and we could get out of the extreme cold.

Looking around the mud flat, it was apparent that some students were about to give up. It was still over eight hours till the sun came up--eight more hours of freezing cold. The chattering teeth and shivering moans (呻吟）of the trainees were so loud that it was hard to hear anything. And then, one voice began to echo (回荡）through the night--one voice raised in song. The song was terribly out of tune, but sung with great enthusiasm. One voice became two, and two became three, and before long everyone in the class was singing. We knew that if one man could rise above the great suffering then others could as well. The instructors threatened us with more time in the mud if we kept up the singing—but the singing went on. And somehow, the mud seemed a little warmer, the wind a little less bitter and the dawn not so far away.

If I have learned anything in my time traveling the world it is the power of hope. The power of one person, Washington, Lincoln, King, Mandela and even a young girl from Pakistan, Malala, can change the world by giving people hope.

So, if you want to change the world, start singing when you're up to your neck in mud.

1.From the passage, we can see that being ordered into the mud was _____.

A. the last part of the training

B. the most useful part of the training

C. the real test of the trainees' intelligence

D. the punishment for the training class

2.The training class singing together ______.

A. inspired the instructors

B. helped them to kill the time

C. kept them from falling into the mud

D. encouraged them to fight their difficulty

3.The writer described his SEAL training experience mainly to tell the readers _____.

A. the power of a large crowd of people    B. the advantage of the training

C. the way to bring about changes    D. the reason to promote singing

4.In the last paragraph, the phrase "up to your neck in mud" most probably means _____ .

A. in an extremely difficult situation    B. in a hard training class

C. in terribly cold weather    D. in a lower social position