be busy to do sth.和be busy doing的区别

be busy doing sth 和be busy to do sth 的区别 be busy to do sth.和be busy doing的区别 be busy doing 和 be busy in doing 的区别? be busy with sth 与be busy to do sth的区别 work on和be busy doing sth.的区别 be busy doing sth和be busy with sth 是be busy doing sth还是be busy to do sth? up to sth 的用法和be busy doing有什么区别吗 be afraid of doing sth be busy doing sth be glad to do buy s 英语翻译allow sb.to do sth.ask sb.to do sth.be busy doing sth.be be busy with sth 与be busy doing sth的区别 be busy with sth 与be busy doing sth的区别 ,可以互换吗