12. C. call off [详解] 详见III,25,26注释。

11. C. blame.[详解]take the blame for 对......承担责任。Take charge of 负责管理 (照顾) 。[注意]charge 前无冠词the.

10. A. concise.

　[详解] concise (=brief; giving much information in few words) 简明扼要的：He gave a concise report of the meeting. (他对会议作了简明扼要的报道。) clear 清楚的。precise (=exact; correctly stated; free form error) 精确的, 明白无误的; Please tell me the precise measurements. (请告诉我精确的尺寸。) elaborate (=worked out with much care; carefully prepared) 精心制作的, 丰盛的：Peter worked out an elaborate scheme for raising the money. (彼得制定了一项详尽得计划来筹集着笔款项。) 孤立地看, 似乎4个形容词均能修饰report, 但从句子的逻辑关系看, 后半句中有only in a few pages but with all the details, 故concise 是最贴切的选择了。

9. B. predominantly.

　[详解] predominantly (=mostly; mainly) 主要地。 previously (=coming earlier in time or order) 先前, 早先; This is better than any solution previously. (这个办法比以前提出的任何解决办法都好。) practically (=really; in a practical way) 实际上。permanently (=going on for a long time) 永久地。

　本题译文：在美国, 华人中有三分之一居住在加利福尼亚洲, 其中主要是在旧金山。

8. B. yet

　[详解] yet 常用于现在完成时的否定句中, 意为“尚, 还”。

7. C. wrecked

　[详解] wreck vt. 撞坏, 毁坏; 1) My son wrecked my car. 2) My car was completely wrecked in the accident.

　sink vt. 下沉, 沉没, 该动词也可作及物动词用, 意为“使下沉”, 但按本题句意看, 用被动语态不妥。 drown 溺死, 淹死： (vt.) He drowned his wife. (vi) He drowned in the river. (他在河里淹死了。) submit 1) (=put oneself under the control of another) 提交, 呈送 (to) ： Should a wife submit herself to her husband? (妻子应顺从他丈夫吗?) 2) (=put forward for option, discussion, decision ect.) 提出 (供评论、讨论决定等) You must submit your request to the committee. 3) (=surrender (to) , give in) 屈服,投降：After being defeated, they submitted to the enemy. (打败后, 他们向敌人投降了。)

6. D. connection

　[详解] lose one's connection to 误了到......地方去的 (汽车、火车、轮船的) 联运; The train was late and I missed my connection.

5. C. comprehensive.

　[详解] comprehensive 完全的无所不包的; comprehensible 能懂的, 可以理解的; understandable 可以理解的, 主要用来指人的行为。understanding 用来指人时, 表示"善于理解别人或别人问题的 (人) 。"注意下面的搭配：a comprehensive map (街区详图) ; a comprehensible remark (听得懂的话) ,an understandable mistake (可以理解的错误) ; an understanding friend (一位能理解人的朋友) 。

4. B. abandoned

　[详解] abandoned (=give up completely) 放弃, 抛弃; 1) The scientist abandoned his research for lack of fund. 2) The sailors abandoned the burning ship

　[注意]abandon 暗指某人对其所抛弃的人或物将会发生什么事情不感兴趣, 如把撞坏的汽车抛弃在路旁。vanish (=suddenly disappear; go out of existence) vi.消失, 绝迹; 1) The airplane vanished into the clouds.2) Many kinds of animals have vanished form the earth. (许多种类的动物以在地球上绝迹。) scatter (=send, go in different direction) 驱使, 使分散; The police scattered the crowed. (警察驱散人群。) (=throw or put in various directions) 撒, 到处放; He scattered his clothes all over the room. reject (=refuse to accept) 拒绝接受; She rejected my suggestion

3. A. powerful

　[详解] powerful (=having or producing great power) 强有力的。在这里四个形容词中, 只有powerful (有效力的) 可与表示药物的名词搭配。influential 有影响的, 有势力的, monstrous 异常大的, vigorous 精力旺盛的, 强健有力的。