17.
A)Travelingtodifferentplacesintheworld.
B)Playinggamesthatchallengeone'smind.
C)Improvingmind-readingstrategies.
D)Readingclassicscientificliterature.
18.
A)Participateindebatesordiscussions.
B)Exposethemselvestodifferentcultures.
C)Discardpersonalbiasesandprejudices.
D)Giveothersfreedomtoexpressthemselves.
19.Questions19to21arebasedonthepassageyouhavejustheard.
A) Why dogs can be faithful friends of humans.
B) The nature of relationships between dogs.
C) The reason a great many people love dogs.
D) How dogs feel about their bonds with humans.
20.
A)Theybehavelikeotheranimalsinmanyways.
B)Theyhaveanunusualsenseofresponsibility.
C)Theycanrespondtohumans'questions.
D)Theycanfallinlovejustlikehumans.
21.
A)Theystaywithonepartnerforlife.
B)Theyhavetheirownjoysandsorrows.
C)Theyexperiencetrueromanticlove.
D)Theyhelphumansinvariousways.