Passage OneQuestions 36 to 40 are based on the following passage. A boat rocks gently in the warm，clear water off the coast of Lizard Island. At night, researchers on board the boat lower into the ocean three large iron traps with raw chicken inside. Video cameras are attached to the traps. The researchers watch and take note of how many nautiluses (鹦鹉螺)，attracted to the meat，swim past the traps overnight: In the morning，the team palls the traps back onto the boat. They measure，tag and photograph captured nautiluses before releasing them. Scientist Peter Ward, of the University of Washington, is leading the study, “We need to know how many nautiluses there are,” he said.Why does the number or creatures matter? Information collected around the world by Ward and Other scientists will help to show if the nautilus is threatened and if the animal should be listed as an endangered species.Nautiluses have survived for million years. But some scientists fear that the animals may be in danger of disappearing. Humans have been killing the animal for its unique shell. The inside of the shell is pearl-colored (珍珠色的)and forms a perfect shape. It is used to make decorations and jewelry. A report showed that the annual number of nautilus-shell products was alarmingly high. So Ward came up with a plan to study and count nautiluses. Four more seagoing research trips are expected to take place in the months ahead. There is much to learn. “We’re really at the tip of the iceberg (冰山)，”De Angelis，of the U.S. Fish and Wildlife Service, says.36. In order to study nautiluses the scientists have to tempt them with _____________ .A. meat B. cameras C. traps D. rocks37. The first paragraph is used mainly to describe _____________ .A. how researchers feed nautilusesB. what attracts nautiluses to the trapsC. what tools are used to get nautilusesD. how researchers study nautiluses38. Humans capture nautiluses because they _____________ . A. have pearls inside their shells B. are rare and delicious C. are easy to capture D. have very special decorative shells39. The reason why Ward made a plan to study nautiluses is that _________________ .A. there were too many nautiluses killed B. nautiluses had been proved to be threatenedC. nautilus was listed as an endangered speciesD. the number of nautiluses was growing40. What does De Angelis mean by saying “We‘re really at the tip of the iceberg”, in the last paragraph？ ______ A. The scientists are confronted with a critical situation.B. The scientists know only a little about nautiluses.C. Their scientific research is at the leading level.D. There is a long way to go to see the whole iceberg.