读以下对话,选择括号中正确的词补全句子。 1 -- Are you good at swimming? --Sure. I live on the riverside. I _______ swim when I was only 5 years old.( should/ could/ might) 2 -- How can I keep fit? --You ________ ( mustn't / needn't / couldn't ) eat so much junk food. 3 -- ________________ ( Must / May / Should ) I borrow your bike? -- Of course. Here is the key. 4-- How _______________ ( may /can / shall ) you make such success? -- By working hard. 5 -- What is the good at? -- She __________ ( can / may / must ) play tennis very well.