And he says the sea floor is, on average, at a depth of 4, 000 meters. And so, as some machines dive far below what people have previously seen, scientists are discovering new species of plants, animals and living things

　　Since the census project began, more than 5,300 new marine animals have been found. Ocean researchers say they hope to catalogue 230,000 species during the census —which some say is only a small part of all the creatures living in the sea.

　　47．Why do the researchers place small markers on many marine creatures?

　　A．To catch them.

　　B．To research them.

　　C．To kill them.

　　D．To protect them.

　　48．From what Ron O’Dor says, we can conclude that

　　.

　　A．human beings only know a little about marine life

　　B．the oceans don’t need to be further explored

　　C．he considers exploring the ocean a dangerous thing

　　D．the marine creatures mainly live on the top of the ocean

　　49．What can we learn from the passage?

　　A．About 2,000 scientists from America are involved in the project.

　　B．The census of sea life will last for ten years.

　　C．230,000 new marine animals have been found.

　　D．The sea floor is at a depth of 400 meters.

　　50．Why does the author write the passage?

【2017届高考英语总复习闯关密训卷 Unit2《Poems》选修6】相关文章：

★ 2014届高考英语一轮复习课时作业(二十六)必修5Module 2《A Job Worth Doing》（外研版）

★ 2014届高考英语一轮复习课时作业(四十六)选修8Module 4《Which English？》（外研版）

★ 【北京专用】2014届高考英语一轮复习方案课时作业：必修3 Unit 5 Canada

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修4 unit4《Body language》

★ 2017届高考英语二轮复习书面表达限时测验：4（含解析）

★ 【北师大版】2014届高考英语一轮复习指导课时作业：Unit 5 A卷 Word版含解析

★ 2014届高考英语一轮复习课时作业(四十一)选修7Module 5《Ethnic Culture》（外研版）

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (59)

★ 2017届高考英语二轮复习大题冲关秘籍语法填空：考纲解读（含解析）

★ 2014届高考英语一轮复习课时作业(三十三)选修6Module 3《Music》（外研版）