1.The common characteristic of fish,amphibians,reptiles,birds,and mammals is that they all have backbones.
(A) lungs n. [解剖] 肺（lung的复数形式）
(B) spines n. [解剖] 脊柱；棘状突起；体刺（spine的复数）
(C) claws n. 爪子（claw的复数）
2.By producing an excess amount of some household articles,a New England colonial family could barter with other families.
(A) share vt. 分享，分担；分配
(B) trade n. 贸易，交易；行业；职业
(C) repair n. 修理，修补；修补部位
3.The province of British Columbia offers visitors breathtaking views of the Canadian Rocky Mountains.
(A)distant adj. 遥远的；冷漠的；远隔的；不友好的，冷淡的
(B)intimate adj. 亲密的；私人的；精通的；有性关系的
(C)stunning adj. 极好的；使人晕倒的；震耳欲聋的
4.Double Eagle 2,the first transatlantic balloon,was greeted by avid crowds in France.
(A) eager adj. 渴望的；热切的；热心的
(B) surging v. 冲击（surge的ing形式）；浪涌
(C) appreciative adj. 感激的；赏识的；有欣赏力的；承认有价值的
5.Some birds have a waxy coating on their feathers that causes water to form beads and slide off.
(A) whiskers v. 使…有须；使…有似须状的东西
(B) streams v. 流淌；急驶；使…飘扬
(C) drops v. 使掉下；滴下；随口漏出（drop的三单形式）
6.By providing legal representation,the American Civil Liberties Union works to defend citizens against breaches of their civil rights.
(A) branches n. [计][核] 分支（branch的复数）；分支机构
(B) exercises n. 练习题，演习；运动
(C) violations n. 违反，妨碍；违规或不雅行为
答案：BBCA CC
详解：
1.backbones
n. 支柱；主干网；决心，毅力；脊椎
You might be taking drastic measures and you've got to have the backbone to do that.
你可能在采取极端措施，而且你得有骨气做它。
2.barter
n. 易货贸易；物物交换；实物交易
Overall, barter is a very inefficient means of organizing transactions.
总的说来，物物交换是一种非常低效的组织交易的方式。
3.breathtaking
adj. 惊人的；惊险的；令人激动的
Some of their football was breathtaking, a delight to watch.
他们踢的足球赛有些场次令人惊叹,看起来赏心悦目。
4.avid
adj. 渴望的，贪婪的；热心的
He misses not having enough books because he's an avid reader.
他遗憾没有足够的书，因为他是一个热爱读书的人。
5.beads
vt. 用珠装饰；使成串珠状
He shakes his head at the thought of this one thing, this single hideous bead on the necklace of his life.
他一边思索着这件事一边摇着他的头，他生活的项链上唯独可怕的一颗珠子。
6.breaches
n. 违背，违反；缺口
Their actions threatened a serious breach in relations between the two countries.
他们的行动有威胁两国关系分裂的危险。