帮我解析下这句英语!Many people agree that they make progress by singing English
Many people agree that they make progress by singing English songs and that it is a good idea to have fun with English.agree后面为什么可以加动词make.and that it is a good…后面这个句子是什么从句?have fun 是动词词组吗.为什么have fun 前面有个to?