单选题 Every modem government, liberal or otherwise, has a specific position in the field of ideas; its stability is vulnerable to critics in proportion to their ability and persuasiveness.
【正确答案】 B
【答案解析】vulnerable“易受攻击的”；A项futile“无用的”；B项susceptible“易受影响的”；C项feasible“可行的”；D项flexible“灵活的”。根据题意，应选B。