第1题: [单项选择]All ______is a continuous supply of electric power. A. that is needed B. what is needed C. which is most important D. for our needs 参考答案:A 答案解析:[分析] 本题考点为定语从句中关系代词的用法。在定语从句中,当先行词是all, something, nothing等不定代词;或先行词前有first,last,only,few,much, some