161. People are destroying the air by adding ____________ to it. A. pollutants B. polluters C. pollution D. polluted 162. 14 percent of primate species are highly ______________. A. danger B. dangerous C. endanger D. endangered 163. The ________ of old buildings should be taken into consideration. A. preserve B. preservation C. preservative D. preserves 164. Animal _________ supporters gathered to protest against hunting. A. protect B. protection C. protective D. protectionist 165. The main threat to the _________ of these creature comes fro their loss of habitat. A. survive B. survivor C. survival D. survivable 166. Jean Fragonard was a French artist _________ portraits of children. A. whose paintings B. who has painted C. who painted D. whose painted 167. The smoke from burning fuels causes pollution if it ________ into the atmosphere. A. releases B. is released C. will be released D. released 168. Portland, Maine, is ____________ the poet spent his early years. A. where B. it where C. where is D. which is where 169. Walkers can unwritting damage the fragile environment _______________. A. that the birds live B. where the birds live in C. which live the birds D. in which the birds live 170. Wild animals __________ in their natural habitat will have a better and longer life than those which are kept in protected areas. A. live B. to live C. living D. lived 171. There should be some measures to protect the humpback whale, _________ an endangered species. A. to consider B. which is considered C. consider D. is considered 172. We should participate in the movement ___________ to conserve the natural environment. A. organized B. to organize C. organizing D. organize 173. The purchase of wild animals _____________. A. have to be ban B. must ban C. should ban D. must be banned 174. The school has been given 20 computers, half of _________ are brand new. A. that B. those C. them D. which 175. The computer, __________ the memory capacity has just been upgraded, is among the latest generations. A. that B. whose C. of which D. which of 176. ________ is more interested in rhythm than in melody ia apparent from hia compositions. A. That Philip Glass B. Philip Glass, who C. Philip Glass D. Because Philip Glass 177. There are over 2,000varieties of snakes, _________ are harmless to humans. A. mostly they B. most of them C. most of which D. which most 178. For many years people have wondered ________ exists elsewhere in the universe. A. that life B. life which C. whether life D. life as it 179. Computers and new methods of communication __________ the modern office. A. have revolutionized B. to have revolutionized C. that have revolutionized D. has revolutionized 180. Seldom _________ each other anymore. A. we have seen B. do we see C. we do see D. we see