He can work it out.请问这里it可以省略吗,为什么

he can work it out quickly. ______ he _________ I can work it out. it happened(chanceed) that he was out 中的that可以省略吗? 请问《we can work it out》的歌词是什么 两个副词可以连用吗?I can work it out easily and quickly. we can work it out 歌词翻译 Can you work it out?脑筋急转弯. we can work it out 中文翻译 英文翻译：I can work it out. It is known to all that he is a good student.这里的that可以省略吗? The problem is very difficult.He can't work it out.(合并为一句） THE problem is very diffcult.he can't work it out .（合并）