题目内容：

Even now, almost a year after their astonishing act of group heroism, the dozens of people who risked their lives to save two boys from drowning in Panama City Beach, are still remembered.

The story began on July 8, 2017. Members of the Ursrey family, eight in total, were enjoying an evening together at the beach. As the sun sank lower on the horizon（地平线）, the two boys—Noah, 11, and Stephen, 8—took their skateboards and walked into the waves without the grown-ups noticing. When the boys were about 70 yards from shore, they realized that the ocean pulled them out to sea. After trying and failing to paddle（涉水）back, they started waving and screaming for help. But the lifeguards had clocked out for the evening.

The boys had been struggling for several minutes when Brittany and Tabatha Monroe, a married couple from Georgia, wandered by. They didn’t see the boys at first, but they heard them.

They jumped into the water and easily reached the brothers, who were still in fairly shallow water. The woman reassured the frightened boys and seized their skateboards, telling them they would be safe and then discovered that they, too, were now in a world of trouble. They couldn’t get back to shore and could barely and only occasionally hit the sandy bottom with their feet. After a few minutes, it was clear to the woman that they were all trapped in a terrible whirlpool.

Then scores of tourists were walking to them, hand in hand, forming a line. Soon the first person held the woman’s hand. In turn, her husband and the two boys joined her. The long line moved slowly until they were back to the safety of the beach.

The rescuers call it the Human Chain. But it was the deeply “human” aspect of the rescuers’ cooperation（合作）that made it so astonishing and successful.

1.What happened to the two boys?

A. They got into deep sea by chance.    B. They couldn’t be seen in the sea.

C. They went out without supper.    D. They met with danger in the sea.

2.What does the underlined word “reassured” in Paragraph 4 mean?

A. Saved.    B. Comforted.    C. Congratulated.    D. Accompanied.

3.Which of the following best describes the water the young couple stayed in?

A. It appeared calm on the surface.    B. It was very deep.

C. It was mixed with sand.    D. It moved fast.

4.What made the four persons in the sea escape the risky situation?

A. Team spirit.    B. Confidence.    C. Good luck.    D. Bravery.