朗读下面短文，体会、领悟情态动词在具体语境中的含义，掌握其形式变化及其用法。
Lucy is an outgoing lady. She can① play many kinds of musical instruments. Actually, she could② play the piano when she was 8 years old. Lucy also keeps taking exercise every day. She says that she has to③ do some sports because she must④ keep slim.
“You shall⑤ get fat soon if you don't take exercise every day.” She usually says to her friends.
As for her, an elegant lady, should⑥ try to keep fit. However, last week, she found that she might⑦ put on weight and she was worried and decided to lose weight. And these days she is always thinking that she may⑧ succeed soon if she tries all her best. However, she is always lack of time because she ought to⑨ take care of her children.
One night after supper, she walked quickly in order to go dancing at the Tomorrow Park but she was late. On her way, she thought that the dancing must have begun⑩， and the coach could have taught or shown? many new moves. She was afraid that her friends might have left? before she got there. She was regretful then. She should have had? supper earlier, or she could have taken a taxi?， and indeed she needn't have taken? a bath in advance. When she reached the park finally, she found nobody was there. She remembered suddenly that it had been reported on the radio that there would be a heavy rain that night.
[用法体悟]
①can在此表示能力。
②could在此表示能力，是can的过去式。
③have to表示“不得不”，强调客观需要。
④must表示“必须”，强调主观想法。
⑤shall表示说话者的意图、允诺、告诫、警告等，常用于陈述句的第二、第三人称。
⑥should表示劝告或建议，意为“应该”。
⑦might在此是may的过去式，表示“可能”。
⑧may表示“可能”。
⑨ought to意为“应该”，表示义务或责任，比should语气重。
⑩must have done表示对过去已经发生的事的肯定推测，意为“一定已经做了某事”。
?could have done表示对过去情况的推测，意为“可能已经做了某事”。
?might have done表示“或许已经做了某事”。
?should have done表示“本应该做某事(但实际上没有做)”，有责备和懊悔之意。
?could have done 意为“本来可以做某事(但实际上没有做)”，有懊悔之意。
?needn't have done表示做了本来不必去做的事情，意为“本不必做某事(但实际上却做了)”。
