12.　 She is an expert on ___________________________ (环境的)issues.

11.　 She had been taught how to react in an ______________________ (紧急情况).

10.　 A ______________________ (大陆)is a large mass of land divided into different countries.

9.　　　 The ________________________ (金字塔)are the huge ancient Egyptian royal tombs built on a square base, with four sloping triangular sides meeting in a point.

8.　　　 She thinks she made a quite good ______________________ (印象)on the judges.

7.　　　 I ________________________ (道歉)to you for not having written earlier.

6.　　　 How did they survive the mental __________________ (残酷).

5.　　　 A ________________________ (最后期限)is the time by which something must be done, or a task completed.

4.　　　 When there is a ______________________ (相似)between two things they are like each other in some way.

3.　　　 There are many ________________________ (冒险的)stories in The Adventures of Tom Sawyer by Mark Twain.