1．(2020·新高考山东卷)They kept their collection at home until it got too big ________ until they died，and then it was given to a museum.
解析： 考查连词。分析句子结构可知，until it got too big和until they died并列，同时结合语境可知，此处表示选择关系，故用连词or。
答案： or
2．(2020·浙江卷1月)It's also that they are on average healthier ________ more productive for longer.
解析： 考查并列连词。结合句意可知，healthier 和more productive 构成并列关系，故填and。
答案： and
3．(2019·全国卷Ⅱ)I work not because I have to，________because I want to.
解析： 考查连词。not...but...不是……而是……。句意：我工作不是因为我必须工作，而是因为我想工作。
答案： but
