给定一篇英文短文，将其中指定的单词替换为指定的同义词。以下是一个例子：将"She walked slowly down the street" 中的"slowly" 替换为"leisurely"。 你需要提供至少三对替换的单词和他们需要被替换的位置。
原文：“He was a great novelist and his books are still popular today. He wrote many classics such as 'The Great Gatsby' and 'Tender Is the Night'." 需替换的位置和词汇： "great" 需替换成 "outstanding" （第一句中）； "popularity" 需替换成 "populace" （第一句中）； "classics" 需替换成 "masterpieces" （第二句中）。
1. "He was an outstanding novelist and his books are still popular with the populace today. He wrote many masterpieces such as 'The Great Gatsby' and 'Tender Is the Night'." 

2. "She spoke eloquently during the presentation and left a strong impression on the audience." 替换 "strong" 为 "powerful"

3. "The CEO's decision to invest in new technology proved vital to the company's success." 替换 "vital" 为 "crucial"

4. "The teacher assigned a challenging task to her students to test their critical thinking skills." 替换 "challenging" 为 "demanding" 

5. "The athlete's exceptional performance during the marathon earned him a gold medal." 替换 "exceptional" 为 "remarkable"