Cloze

Directions: In this part, there is a passage with ten blanks. For each blank there are four choices marked A, B, C, and D. Choose the best answer for each blank.

     Zoos have become an important site for the preservation and protection of wildlife resources,  those species that are endangered. , many zoos displayed live animals for public entertainment. Presently some zoos have become scientific and educational  that have contributed to the understanding and conservation of wild animal populations.  the challenges facing modern zoos are the cost of upgrading old facilities, the struggle to obtain  operating funds, and the need to attract more visitors to new and entertaining exhibits.
     Many  zoos in American dries have undergone renovation (翻新) during the last decades of the twentieth century. Among the recent trends in zoo  is the construction of new enclosures that resemble natural habitats (栖息地). The replacement of traditional steel bars and concrete floors  appropriately designed surroundings improves visitor appreciation of the animals. Such renovations may.  stress on animals and allow them to interact with one another more naturally.
     Several major zoos conduct captive propagation programs. A captive propagation program includes the breeding of  zoo or wild animals to obtain offspring, usually for release to  or for transfer to other zoos. Captive breeding is one method of  some species from extinction.
     Zoos have expanded and improved public education programs also, with education departments that develop programs  zoo exhibits. Public activities include in-school programs, zoo tours, special events, and websites. The Zoological Society of New York, for example, conducted a major project with a Western African government to monitor an elephant herd it moved throughout its range.
     The importance of zoos will increase as natural habitats are diminishing. Through their efforts  conservation, education, and environmental advocacy, zoos will continue to play a critical role in wildlife preservation throughout the world.