忙于做某事为什么要用be busy doing sth 可以用be busy to do sth吗

忙于做某事为什么要用be busy doing sth 可以用be busy to do sth吗 忙与做某事be busy doing sth\with sth 用be busy doing sth.句型造句 be busy doing sth 和be busy to do sth 的区别 是be busy doing sth还是be busy to do sth? 英语翻译allow sb.to do sth.ask sb.to do sth.be busy doing sth.be be afraid of doing sth be busy doing sth be glad to do buy s be busy with sth 与be busy doing sth的区别 ,可以互换吗 花费时间做某事为什么要用spend time doing sth可以用spend time to do sth吗 be busy in doing sth be busy doing sth 例句 be busy to do sth.和be busy doing的区别