1 . Experts believe that a significant c________ factor in many accidents is the lack of sleep among workers.   (根据首字母单词拼写)

2 . This information must not be disclosed without ________ (先前的) written consent. （根据汉语提示单词拼写）

3 . I am very ________ (感激) to you for having taken so much trouble. （根据汉语提示单词拼写）

4 . The two pictures are similar，although not________ (相同的). (根据汉语提示单词拼写）

5 . The woman was so ________(敏感) that even the clicking sound of the mouse upset her. (根据汉语提示单词拼写）

6 . As an ________(外向的) girl，I get along well with my classmates. (根据汉语提示单词拼写）

7 . Putonghua is the o________ language of China, and it’s winning increasing popularity around the world. (根据首字母单词拼写)

8 . I think Martin is a________ to smoking. He just can’t seem to quit it. (根据首字母单词拼写)

9 . He was a keen amateur (业余的) photographer for many years before he turned p________. (根据首字母单词拼写)

10 . The kidney plays a ________ (极其重要的) role in the removal of waste products from the blood.