It is difficult to do sth It is difficult to finish the work in an hour. 这个句子真正的主语是to finish the work in an hour,其实这个句子To finish the work in an hour is difficult.It 是做形式主语的.句子要有谓语啊,所以要有is
基本句型 it is adj. (for/of sth)to do sth. 主语to do sth,所以实际是To do sth. is... 做什么是怎么样的 英文中为避免头重脚轻,主语后置。有强调adj。的意思 It is difficult to finish the work in an hour. 一小时内完成工作很难。 另外,区别 for 和o...