分类：教育/科学-学习帮助
问题：１．Thesingeranddancer_____inBeiji? 
１．The singer and dancer _____in Beijing now.A.isB.are.was D.were答案选Ａ2.The Old Man and The Sea _____ by Ernest Hemingway in 1952.A.was writtenB.were writtenC.was writingD.were writing 答案是Ａ3.Nobody but Tim and Bill______in the playground at that time.A.i１．The singer and dancer _____in Beijing now.A.isB.are.was D.were答案选Ａ2.The Old Man and The Sea _____ by Ernest Hemingway in 1952.A.was writtenB.were writtenC.was writingD.were writing 答案是Ａ3.Nobody but Tim and Bill______in the playground at that time.A.is B.areC.wasD.were答案是Ｃ同样是and为什么单复数用的不同？哪位知识人士能够教教我啊～谢谢！
回答：不是单复数问题，是时态。第一个是现在，后面2个是过去。