A.Fe3O4.
B.Fe(OH)2.
C.FeO.
D.Fe2O3.

A.Na2SO4.
B.NaCl.
C.HCl.
D.Na2CO3.

A.Urbanization minimizes risks for economic, cultural and societal development.
B.Urbanization makes water supply system both efficient and effective.
C.Weather and climate in the city will not be improved.
D.People may come up with new ideas for innovation.

A.Population
B.Development
C.Urbanization
D.Unsanitary condition

A.meaningful
B.severe
C.deep
D.right

A.Infrastructure and Economic Activities in Cities
B.The Risks of Rapid Urbanization in Developing Countries
C.What Has Driven Rapid Urbanization?
D.The Global Risks 2015 Report on Developing Countries

A.Infrastructure and Economic Activities in Cities
B.The Risks of Rapid Urbanization in Developing Countries
C.What Has Driven Rapid Urbanization?
D.The Global Risks 2015 Report on Developing Countries

A.The primary aim of a travel guide is for suggestions when travellers are in a hurry.
B.Before embarking on a journey, most people bring with them a guidebook in case they get into trouble.
C.The information found in a guidebook is always up-to-date and reliable.
D.Users cannot obtain information about the opening times of museums on the Internet.

A.purposes
B.books
C.times
D.guides

A.publishers usually spend a year researching information needed for their books
B.many publishers still prefer an already crowded market for their books
C.publishers' actions may prove incomprehensible to lay people
D.some publishers find almost as many resources to the update and redesign of their books as to the creation of them