用下列单词的适当形式填空。

abandon, desert, forsake, quit

1. He _____ himself to deep despair when the news came that his wife had been killed in a car accident.

2. If I don't get more money, I'll _____.

3. He had made it clear to his wife that he would never _____ her.

4. She lost the next five games, and the set, as her confidence abruptly _____ her.