1. All living organisms, regardless of their unique identity, have certain biological, chemical, and physical characteristics in common. A) as a result of B) considering C) on purpose D) whatever 2. The most pressing problem any economic system faces is how to use its scarce resources. A) puzzling B) difficult C)terrifying D) urgent 3. The Klondike was the scene of one of the biggest gold rushes the world has ever known. A） location B)view C) event D) landscape 4. Of the reptile groups, the snake group was the final one to appear. A) last B)best C) ugliest D)longest 5. Colleges and universities usually give diplomas or certificates to students who complete course requirements satisfactorily. A) responsibly B) acceptably C) patiently D)respectfully 6. A will is a document written to ensure that the wishes of the deceased are realized A) fulfilled B) affiliated C) advocated D) received 7. She has been the subject of massive media coverage. A) extensive B) negative C) responsive D) explosive 8. The conference explored the possibility pf closer trade links. A) rejected B) investigated C) proposed D) postponed 9. Experts generally agree that diet has an important bearing on one’s health. A) result B) factor C) cause D) influence 10. I expect that she will be able to cater for your particular needs. A) meet B) reach C)provide D) fill 11. John is collaborating with Mary in writing a book. A) cooperating B) merging C) combining D) associating 12. Mary lost control of her car and collided with a tree. A) came across B) ran into C) met D) knocked 13. Mary was compelled to take in washing to help support her family. A) pleaded B) appealed C) forced D)instructed 14. The child couldn’t comprehend the advanced textbook. A) interpret B) read C) understand D) translate 15. I warned him to keep the matter confidential. A) private B) safe C) personal D) secret Keys: DDAAB AABDA ABCCD