It has been...（一段时间）+ since
It has been...（一段时间）+ sinceIt has been...（一段时间）+ since引导的从句/自从……以来已经……了该句型中since引导的时间状语从句常用一般过去时。例如：It's twenty years si
2016-12-24
It is/was + 形容词 + for sb. to do
It is/was + 形容词 + for sb. to doIt is/was + 形容词 + for sb. to do.../做某事对某人来说……It是形式主语，真正的主语是不定式to do sth。例如：It's not easy for us to study English well.
2016-12-24
It seems that...似乎……/看样子
It seems that...似乎……/看样子It seems that...似乎……/看样子……；It appears to sb. that.../在某人看来，似乎……此句中的it是主语，that引导的是表语
2016-12-24
It takes/took sb. time/money to do
It takes/took sb. time/money to doIt takes/took sb. time/money to do.../做某事花了某人……时间/金钱it是形式主语，真正的主语是动词不定式to do sth。例如：It takes her fifteen minutes to
2016-12-24
keep/prevent/stop sb. from doing/阻止某人做
keep/prevent/stop sb. from doing/阻止某人做keep/prevent/stop sb. from doing/阻止某人做……Please keep the children from swimming in the sea.请别让孩子到海里游泳。The big noise outside
2016-12-24
make/have/let sb. do../让某人做某事
make/have/let sb. do../让某人做某事make/have/let sb. do../让某人做某事make/have/let意为“使”时，其后要有不带to的动词不定式。例如： He made me work ten hours a day. 他让我每天工作10小时。
2016-12-24
not...until.../直到……才……
not...until.../直到……才……not...until.../直到……才……until后可跟名词或从句，表示时间。例如：He didn't come until late in the evening. 他直到晚上
2016-12-24
spend money/time on sth./(in) doing sth
spend money/time on sth./(in) doing sthspend money/time on sth./(in) doing sth. 在某物/在做某事上花了……时间/金钱其中in可以省略，通常主语为“人”。例如：I spent five yuan on
2016-12-24