1 . A little stress caused by the exams is useful as it can ________ (sharp) your mind and motivate you to do well. (所给词的适当形式填空)

2 . ________(sharp) up your public speaking skills, so that you can share your book with relevant audiences. (用所给词的适当形式填空)

3 . The problem with pencils is that you have to __________(sharp) them after being used for some time. (所给词的适当形式填空)

5 . He did a training course to ______ (sharp) his skills. (所给词的适当形式填空)

6 . She worked as a salesperson for three years, s______________(使提高)her business skills. (根据中英文提示单词拼写)

7 . He ________ (sharpen) his knife in order that he cut meat easily . （所给词的适当形式填空）

8 . As is often said, reading can help to ________ (sharp) our minds. （所给词的适当形式填空）