On Feb. 5, five members of a research team dived to photograph rare cave fish in the underwater caves, but on their return at 7 p. m. , two team members, both surnamed Zhou, were found to be missing.
Liang Liang, a rescue officer, said, "The complex environment of the cave was unknown to us, which was the biggest challenge."
Visibility was limited to just 3 metres, forcing rescuers to use portable lights. With water depths reaching 18 metres, rescuers used five 200-metre reels to lay guide ropes from the cave entrance into the water. They also needed boats to stay on the water.
"The exact places of the lost members were unclear, and we could only hear the sound of knocking on the rock walls, to find a general direction," said Xu Shide, a diver. The elder Zhou was found at 4:30 a. m. on Feb. 6, in an air pocket 16 metres below the water surface and about 300 metres from the cave's entrance. After 90 minutes of further efforts, he was finally outside the cave.
Xu Shide said the younger Zhou was trapped much deeper, so they scanned more than 10 underwater air pockets. Fortunately, around 6:50 p. m. on February 8, they discovered younger Zhou in another air pocket 28 metres deep and about 500 metres from the entrance.
"The rescue team was professional, with cave diving skills and advanced equipment," said Tang Junwen, a cave diver. "Plus, these caves weren't completely enclosed, allowing lost people to find breathable air pockets."
Rescuers warned that getting lost is a major risk of cave exploration. Proper preparation, including plenty of food and communication tools, is important before entering caves. Explorers should also have outdoor survival experience.
任务一 阅读填表
阅读短文,根据所读内容,在文章后题的空格里填入最恰当的内容。注意:1～5题每个空格只填1个单词,第6题词数不少于20。

任务二 阅读理解
What is the purpose of writing the passage?
A.To tell us to be careful when exploring caves.
B.To teach us how to dive in caves.
C.To show cave fish are very useful.
D.To ask more people to visit caves.